Prehistoric Park Animal Field Guide Volume 1

by WildExpert24

As a Prehistoric Park employee, you get the privilege to work with the likes of previously extinct animals. However, if you want to survive longer than five minutes, then you need to know its inhabitants. From the world of Cartoon's Prehistoric Park, this Guide will give you info on behavior, diet, lifespan, and more. Welcome to the Ultimate Prehistoric Guidebook.

2. Tyrannosaurus

Tyrannosaurus rex

Scientific Classification

Kingdom: Animalia

Phylum: Chordata

Clade: Dinosauria

Clade: Saurischia

Clade: Theropoda

Family: Tyrannosauridae

Subfamily: Tyrannosaurinae

Genus: Tyrannosaurus

Type Species: Tyrannosaurus rex meaning "Tyrant Lizard King."

Described by Henry Fairfield Osborn, 1905

Common Names: T. Rex, Tyrannosaurus, Rex, Rexes, Tyrannosaurs, Tyrannosaur, and T-Rex.

Synonyms:

Genus Synonyms:

-Dinotyrannus, Olshevsky, 1995

-Dynamosaurus, Osborn, 1905

-Manospondylus, Cope, 1892

-Nanotyrannus, Bakker, Williams & Currie, 1988

-Stygivenator, Olshevsky, 1995

-Tarbosaurus?, Maleev, 1955b

Species Synonym:

-Aublysodon amplus?, Marsh, 1892

-Deinodon amplus?, (Marsh, 1892) Hay, 1902

-Manospondylus amplus?, (Marsh, 1892) Olshevsky, 1978

-Stygivenator amplus?, (Marsh, 1892) Olshevsky, 1995

-Tyrannosaurus amplus?, (Marsh, 1892) Kuhn, 1939

-Aublysodon cristatus?, Marsh, 1892

-Deinodon cristatus?, (Marsh, 1892) Hay, 1902

-Stygivenator cristatus?, (Marsh, 1892) Olshevsky, 1995

-Manospondylus gigas, Cope, 1892

-Dynamosaurus imperiosus, Osborn, 1905

-Tyrannosaurus imperiosus, (Osborn, 1905) Swinton, 1970

-Gorgosaurus lancensis, Gilmore, 1946

-Albertosaurus lancensis, (Gilmore, 1946) Russell, 1970

-Deinodon lancensis, (Gilmore, 1946) Kuhn, 1965

-Aublysodon lancensis, (Gilmore, 1946) Charig in Appleby, Charig, Cox, Kermack & Tarlo, 1967

-Nanotyrannus lancensis, (Gilmore, 1946) Bakker, Williams & Currie, 1988

-Albertosaurus "megagracilis", Paul, 1988a (nomen nudum)

-Dinotyrannus megagracilis, Olshevsky, 1995

-Aublysodon molnaris, Paul, 1988a

-Aublysodon molnari, Paul, 1988a emend Paul, 1990

-Stygivenator molnari, (Paul, 1988a emend Paul, 1990) Olshevsky, 1995

Current Park Population: 4 (2 adults, 1 Male and 1 Female, and 2 juveniles, 1 male and 1 female).

Park Diet: pre-killed cattle, goats, sheep, pigs, and meat slabs.

Natural Diet: Hadrosaurs, ceratopsians, ornithomimids, Pachycephalosaurs, small dinosaurs, reptiles, fish, amphibians, possibly young sauropods, and occasionally cannibalistic preying on others of their kind.

Lifespan: 28 Years Maximum possibly 50 Years.

Habitat: Open Subtropical Forest and Swamp floodplains with large amounts of food and water supplies.

Native Ecosystem: Western North America, on what was then an island continent known as Laramidia. Hell Creek Formation, Lance Formation, Ferris Formation, Willow Creek Formation, Southwestern Alberta, Saskatchewan, Canada, Montana, South Dakota, Wyoming, Alberta, Saskatchewan, and possibly New Mexico and Texas, USA, 68-66 Million Years Ago, Maastrichtian Stage.

Breeding Season: Year-round.

Gestation Period: Four to six months.

Eggs Laid: One to fifteen, occasionally sixteen depending on the food supply.

Hatching Time: One to three weeks, depending on the climate.

Danger Level: Extremely dangerous proceed with extreme caution, 10 out of 10.

Park Five Star Rating: 5 Stars.

Summary: "Tyrannosaurus rex is the most famous prehistoric animal on the planet, and is usually what comes to mind when someone hears the word "dinosaur". Tyrannosaurus Rex is one of the world's most famous dinosaurs, along with Triceratops, Velociraptor, Stegosaurus, Apatosaurus, Brachiosaurus, Spinosaurus, and Brontosaurus. As the archetypal theropod, Tyrannosaurus has been one of the best-known dinosaurs since the early 20th century and has been featured in film, advertising, postal stamps, and many other media. Tyrannosaurus is among the largest carnivores to ever walk the earth and the apex predator of Hell Creek. It possesses binocular vision, acute hearing, and an incredible sense of smell. Although adult T. rex is an enormous bulky powerhouse, young tyrannosaurs are extremely lithe in comparison, with thin snouts and long ostrich-like legs used for pursuing fast prey. It was the last known member of the tyrannosaurids and among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event.

"There is a sketch of Sid scaring Ronnie Anne wearing a T. Rex head although it resembles the Jurassic Park/World Style T. Rex."

"There isn't a more iconic dinosaur than the T. rex, even people who don't know the difference between herbivore and carnivore know all about the Tyrannosaurus rex. And when you see it up close, feel its gaze... you understand why the T. rex was the ruler of the Cretaceous period." -Thomas Tran.

History of Research:

Earliest Finds: Teeth from what is now documented as a Tyrannosaurus rex were found in 1874 by Arthur Lakes near Golden, Colorado. In the early 1890s, John Bell Hatcher collected postcranial elements in eastern Wyoming. The fossils were believed to be from the large species Ornithomimus grandis (now Deinodon), but are now considered T. rex remains.

In 1892, Edward Drinker Cope found two vertebral fragments of a large dinosaur. Cope believed the fragments belonged to an "agathaumid" (ceratopsid) dinosaur, and named them Manospondylus gigas, meaning "giant porous vertebra", about the numerous openings for blood vessels he found in the bone. The M. gigas remains were, in 1907, identified by Hatcher as those of a theropod rather than a ceratopsid.

Henry Fairfield Osborn recognized the similarity between Manospondylus gigas and T. rex as early as 1917, by which time the second vertebra had been lost. Owing to the fragmentary nature of the Manospondylus vertebrae, Osborn did not synonymize the two genera, instead considering the older genus indeterminate. In June 2000, the Black Hills Institute found around 10% of a Tyrannosaurus skeleton (BHI 6248) at a site that might have been the original M. gigas locality.

Skeleton Discovery and Naming: Barnum Brown, assistant curator of the American Museum of Natural History, found the first partial skeleton of T. rex in eastern Wyoming in 1900. Brown found another partial skeleton in the Hell Creek Formation in Montana in 1902, comprising approximately 34 fossilized bones. Writing at the time Brown said "Quarry No. 1 contains the femur, pubes, humerus, three vertebrae and two undetermined bones of a large Carnivorous Dinosaur not described by Marsh. ... I have never seen anything like it from the Cretaceous". Henry Fairfield Osborn, president of the American Museum of Natural History, named the second skeleton T. rex in 1905. The generic name is derived from the Greek words τύραννος (tyrannos, meaning "tyrant") and σαῦρος (sauros, meaning "lizard"). Osborn used the Latin word rex, meaning "king", for the specific name. The full binomial, therefore, translates to "tyrant lizard the king" or "King Tyrant Lizard", emphasizing the animal's size and presumed dominance over other species of the time.

Osborn named the other specimen Dynamosaurus imperiosus in a paper in 1905. In 1906, Osborn recognized that the two skeletons were from the same species and selected Tyrannosaurus as the preferred name. The original Dynamosaurus material resides in the collections of the Natural History Museum, London. In 1941, the T. rex type specimen was sold to the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania, for $7,000. Dynamosaurus would later be honored by the 2018 description of another species of tyrannosaurid by Andrew McDonald and colleagues, Dynamoterror dynastes, whose name was chosen about the 1905 name, as it had been a "childhood favorite" of McDonald's.

From the 1910s through the end of the 1950s, Barnum's discoveries remained the only specimens of Tyrannosaurus, as the Great Depression and wars kept many paleontologists out of the field.

Resurgent Interest: Beginning in the 1960s, there was renewed interest in Tyrannosaurus, resulting in the recovery of 42 skeletons (5–80% complete by bone count) from Western North America. In 1967, Dr. William MacMannis located and recovered the skeleton named "MOR 008", which is 15% complete by bone count and has a reconstructed skull displayed at the Museum of the Rockies. The 1990s saw numerous discoveries, with nearly twice as many finds as in all previous years, including two of the most complete skeletons found to date: Sue and Stan.

Sue Hendrickson, an amateur paleontologist, discovered the most complete (approximately 85%) and largest Tyrannosaurus skeleton in the Hell Creek Formation on August 12, 1990. The specimen Sue, named after the discoverer, was the object of a legal battle over its ownership. In 1997, the litigation was settled in favor of Maurice Williams, the original landowner. The fossil collection was purchased by the Field Museum of Natural History at auction for $7.6 million, making it the most expensive dinosaur skeleton until the sale of Stan for $31.8 million in 2020. From 1998 to 1999, Field Museum of Natural History staff spent over 25,000 hours taking the rock off the bones. The bones were then shipped to New Jersey where the mount was constructed, then shipped back to Chicago for the final assembly. The mounted skeleton opened to the public on May 17, 2000, in the Field Museum of Natural History. A study of this specimen's fossilized bones showed that Sue reached full size at age 19 and died at the age of 28, the longest estimated life of any tyrannosaur known.

Another Tyrannosaurus, nicknamed Stan (BHI 3033), in honor of amateur paleontologist Stan Sacrison, was recovered from the Hell Creek Formation in 1992. Stan is the second most complete skeleton found, with 199 bones recovered representing 70% of the total. This tyrannosaur also had many bone pathologies, including broken and healed ribs, a broken (and healed) neck, and a substantial hole in the back of its head, about the size of a Tyrannosaurus tooth.

In 1998, Bucky Derflinger noticed a T. rex toe exposed above ground, making Derflinger, who was 20 years old at the time, the youngest person to discover a Tyrannosaurus. The specimen, dubbed Bucky in honor of its discoverer, was a young adult, 3.0 meters (10 ft.) tall and 11 meters (35 ft) long. Bucky is the first Tyrannosaurus to be found that preserved a furcula (wishbone). Bucky is permanently displayed at The Children's Museum of Indianapolis.

In the summer of 2000, crews organized by Jack Horner discovered five Tyrannosaurus skeletons near the Fort Peck Reservoir. In 2001, a 50% complete skeleton of a juvenile Tyrannosaurus was discovered in the Hell Creek Formation by a crew from the Burpee Museum of Natural History. Dubbed Jane (BMRP 2002.4.1), the find was thought to be the first known skeleton of a pygmy tyrannosaurid, Nanotyrannus, but subsequent research revealed that it is more likely a juvenile Tyrannosaurus and the most complete juvenile example known; Jane is exhibited at the Burpee Museum of Natural History. In 2002, a skeleton named Wyrex, discovered by amateur collectors Dan Wells and Don Wyrick, had 114 bones and was 38% complete. The dig was concluded over 3 weeks in 2004 by the Black Hills Institute with the first live online Tyrannosaurus excavation providing daily reports, photos, and video.

In 2006, Montana State University revealed that it possessed the largest Tyrannosaurus skull yet discovered (from a specimen named MOR 008), measuring 5 feet (152 cm) long. Subsequent comparisons indicated that the longest head was 136.5 centimeters (53.7 in) (from specimen LACM 23844) and the widest head was 90.2 centimeters (35.5 in) (from Sue).

Footprints: Two isolated fossilized footprints have been tentatively assigned to T. rex. The first was discovered at Philmont Scout Ranch, New Mexico, in 1983 by American geologist Charles Pillmore. Originally thought to belong to a hadrosaurid, examination of the footprint revealed a large 'heel' unknown in ornithopod dinosaur tracks, and traces of what may have been a hallux, the dewclaw-like fourth digit of the tyrannosaur foot. The footprint was published as the ichnogenus Tyrannosauripus pillmorei in 1994, by Martin Lockley and Adrian Hunt. Lockley and Hunt suggested that it was very likely the track was made by a T. rex, which would make it the first known footprint from this species. The track was made in what was once a vegetated wetland mudflat. It measures 83 centimeters (33 in) long by 71 centimeters (28 in) wide.

A second footprint that may have been made by a Tyrannosaurus was first reported in 2007 by British paleontologist Phil Manning, from the Hell Creek Formation of Montana. This second track measures 72 centimeters (28 in) long, shorter than the track described by Lockley and Hunt. Whether or not the track was made by Tyrannosaurus is unclear, though Tyrannosaurus is the only large theropod known to have existed in the Hell Creek Formation.

A set of footprints in Glenrock, Wyoming dating to the Maastrichtian stage of the Late Cretaceous and hailing from the Lance Formation were described by Scott Persons, Phil Currie, and colleagues in 2016, and are believed to belong to either a juvenile T. rex or the dubious tyrannosaurid Nanotyrannus lancensis. From measurements and based on the positions of the footprints, the animal was believed to be traveling at a walking speed of around 2.8 to 5 miles per hour and was estimated to have a hip height of 1.56 m (5.1 ft) to 2.06 m (6.8 ft). A follow-up paper appeared in 2017, increasing the speed estimations by 50–80%.

Description: Like other tyrannosaurids, Tyrannosaurus was a bulky bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hind limbs, the forelimbs of Tyrannosaurus were short but unusually powerful for their size, and they had two clawed digits. They often get scars from battles with their prey and other T. Rexes.

Adults are mostly covered with scaly skin with black sparse filament bristles on the back of their heads, neck, shoulder, and arm regions, back, thigh regions, and tail. They are dark brown with black striping and spotted patterns with striping on the tail, a white underbelly, a mottled face with it black tip at the end of the snout, and a mix of light orange and dark brown striping, the eyes have a light orange orbital eye ring and black markings surrounding the eyes, thighs of the legs were black striped and bronze-like yellow, the keratin running down its nose, orbital hornlets, and brow, gray jugular horns on the cheeks, and unlike most depictions, the teeth were covered with scaly like lips. Males are larger in weight and length while Females are Taller.

Males have longer bigger thin bristle manes, the mottled face is a mix of yellow-orange and dark brown stripes and blotches, the sides of the neck have red patches that go down the neck, a red gular sac throat, and it has bumpy keratin running down its nose, orbital hornlets, and brow which was bright orange more pronounced in its large size and horn-like and measured up to 10 feet tall and 12.4 meters long.

Females have a short bristle mane and a peach-mottled face with dark brown spots and stripes. Measuring up to 12 feet tall and 12 meters long. The keratin ran down its nose, orbital hornlets, and brow which was light orange.

Sub-adults look identical to the adults but are about 9 feet tall and 8 meters long, their keratin nose, orbital hornlets, brow, and face are light peach and faces, and they have a short mane of light brown proto-feathers on their neck, and the rest of the upper body, all the way to its tail, shoulder region, and arms were thin bristle like filament feathering.

Adolescents resemble adults in color but with dark pale faces, thinner muzzles, bronze yellow longer legs, a lighter build, and light brown proto-feather manes on the necks and arms.

Hatchlings are covered in a coat of downy feathering often tan with light brown stripes, a pale mottled face, bronze yellow colored legs, and a black-tipped tail.

Size: T. rex was one of the largest land carnivores of all time. One of the largest and the most complete specimens, nicknamed Sue (FMNH PR2081), is located at the Field Museum of Natural History in Chicago. Sue measured 12.3–12.4 m (40.4–40.7 ft) long, was 3.66–3.96 meters (12–13 ft) tall at the hips, and according to the most recent studies, using a variety of techniques, maximum body masses have been estimated approximately 8.4 metric tons (9.3 short tons). A specimen nicknamed Scotty (RSM P2523.8), located at the Royal Saskatchewan Museum is reported to measure 13 m (43 ft) in length. Using a mass estimation technique that extrapolates from the circumference of the femur, Scotty was estimated as the largest known specimen at 8.87 metric tons (9.78 short tons) in body mass.

Not every adult Tyrannosaurus specimen recovered is as big. Historically average adult mass estimates have varied widely over the years, from as low as 4.5 metric tons (5.0 short tons), to more than 7.2 metric tons (7.9 short tons), with most modern estimates ranging between 5.4 metric tons (6.0 short tons) and 8.0 metric tons (8.8 short tons).

Skull: The largest known T. rex skulls measure up to 1.52 meters (5 ft) in length. Large fenestrae (openings) in the skull reduced weight, as in all carnivorous theropods. In other respects, Tyrannosaurus's skull was significantly different from those of large non-tyrannosaurid theropods. It was extremely wide at the rear but had a narrow snout, allowing unusually good binocular vision. The skull bones were massive and the nasals and some other bones were fused, preventing movement between them; but many were pneumatized (contained a "honeycomb" of tiny air spaces) and thus lighter. These and other skull-strengthening features are part of the tyrannosaurid trend towards an increasingly powerful bite, which easily surpasses that of all non-tyrannosaurids. The tip of the upper jaw was U-shaped (most non-tyrannosauroid carnivores had V-shaped upper jaws), which increased the amount of tissue and bone a tyrannosaur could rip out with one bite, although it also increased the stresses on the front teeth.

The teeth of T. rex displayed marked heterodonty (differences in shape). The premaxillary teeth, four per side at the front of the upper jaw, were closely packed, D-shaped in cross-section, had reinforcing ridges on the rear surface, were incisiform (their tips were chisel-like blades), and curved backward. The D-shaped cross-section, reinforcing ridges, and backward curve reduced the risk that the teeth would snap when the Tyrannosaurus bit and pulled. The remaining teeth were robust, like "lethal bananas" rather than daggers, more widely spaced, and also had reinforcing ridges. Those in the upper jaw, twelve per side in mature individuals, were larger than their counterparts of the lower jaw, except at the rear. The largest found so far is estimated to have been 30.5 centimeters (12 in) long including the root when the animal was alive, making it the largest tooth of any carnivorous dinosaur yet found. The lower jaw was robust. Its front dentary bone bore thirteen teeth. Behind the tooth row, the lower jaw became notably taller. The upper and lower jaws of Tyrannosaurus, like those of many dinosaurs, possessed numerous foramina, or small holes in the bone. Various functions have been proposed for these foramina, such as a crocodile-like sensory system or evidence of extra-oral structures such as scales or potentially lips, with subsequent research on theropod tooth wear patterns supporting such a proposition.

Skeleton: The vertebral column of Tyrannosaurus consisted of ten neck vertebrae, thirteen back vertebrae, and five sacral vertebrae. The number of tail vertebrae is unknown and could well have varied between individuals but probably numbered at least forty. Sue was mounted with forty-seven of such caudal vertebrae. The neck of T. rex formed a natural S-shaped curve like that of other theropods. Compared to these, it was exceptionally short, deep, and muscular to support the massive head. The second vertebra, the axis, was especially short. The remaining neck vertebrae were weakly opisthocoelous, i.e. with a convex front of the vertebral body and a concave rear. The vertebral bodies had single pleurocoels, and pneumatic depressions created by air sacs, on their sides. The vertebral bodies of the torso were robust but with a narrow waist. Their undersides were keeled. The front sides were concave with a deep vertical trough. They had large pleurocoels. Their neural spines had very rough front and rear sides for the attachment of strong tendons. The sacral vertebrae were fused, both in their vertebral bodies and neural spines. They were pneumatized. They were connected to the pelvis by transverse processes and sacral ribs. The tail was heavy and moderately long, to balance the massive head and torso and to provide space for massive locomotor muscles that attached to the thighbones. The thirteenth tail vertebrae formed the transition point between the deep tail base and the middle tail and were stiffened by a rather long front articulation process. The underside of the trunk was covered by eighteen or nineteen pairs of segmented belly ribs.

Classification: Tyrannosaurus is the type genus of the superfamily Tyrannosauroidea, the family Tyrannosauridae, and the subfamily Tyrannosaurinae; in other words, it is the standard by which paleontologists decide whether to include other species in the same group. Other members of the tyrannosaurine subfamily include the North American Daspletosaurus and the Asian Tarbosaurus, both of which have occasionally been synonymized with Tyrannosaurus. Tyrannosaurids were once commonly thought to be descendants of earlier large theropods such as megalosaurs and carnosaurs, although more recently they were reclassified with the generally smaller coelurosaurs.

Many phylogenetic analyses have found Tarbosaurus bataar to be the sister taxon of T. rex. The discovery of the tyrannosaurid Lythronax further indicates that Tarbosaurus and Tyrannosaurus are closely related, forming a clade with fellow Asian tyrannosaurid Zhuchengtyrannus, with Lythronax being their sister taxon. A further study from 2016 by Steve Brusatte, Thomas Carr, and colleagues, also indicates that Tyrannosaurus may have been an immigrant from Asia, as well as a possible descendant of Tarbosaurus.

Additional Species: In 1955, Soviet paleontologist Evgeny Maleev named a new species, Tyrannosaurus bataar, from Mongolia. By 1965, this species was renamed as a distinct genus, Tarbosaurus bataar. While most paleontologists continue to maintain the two as distinct genera, some authors such as Thomas Holtz, Kenneth Carpenter, and Thomas Carr argue that the two species are similar enough to be considered members of the same genus, with the Mongolian taxon having the resulting binomial of Tyrannosaurus bataar.

In 2001, various tyrannosaurid teeth and a metatarsal unearthed in a quarry near Zhucheng, China were assigned by Chinese paleontologist Hu Chengzhi to the newly erected species Tyrannosaurus zhuchengensis. However, in a nearby site, a right maxilla and left jawbone were assigned to the newly erected tyrannosaurid genus Zhuchengtyrannus in 2011. T. zhuchengensis may be synonymous with Zhuchengtyrannus. In any case, T. zhuchengensis is considered to be a nomen dubium as the holotype lacks diagnostic features below the level Tyrannosaurinae.

In a 2022 study, Gregory S. Paul and colleagues argued that Tyrannosaurus rex, as traditionally understood, actually represents three species: the type species Tyrannosaurus rex, and two new species: T. imperator (meaning "tyrant lizard emperor") and T. regina (meaning "tyrant lizard queen"). The holotype of the former (T. imperator) is the Sue specimen, and the holotype of the latter (T. regina) is Wankel rex. The division into multiple species was primarily based on the observation of a very high degree of variation in the proportions and robusticity of the femur (and other skeletal elements) across cataloged T. rex specimens, more so than that observed in other theropods recognized as one species. Differences in general body proportions representing robust and gracile morphotypes were also used as a line of evidence, in addition to the number of small, slender incisor teeth in the dentary, as based on tooth sockets. Specifically, the paper's T. rex was distinguished by robust anatomy, a moderate ratio of femur length vs circumference, and the possession of a singular slender incisiform dentary tooth; T. imperator was considered to be robust with a small femur length to circumference ratio, and two of the slender teeth; and T. regina was a gracile form with a high femur ratio and one of the slender teeth. It was observed that variation in proportions and robustness became more extreme higher up in the sample, stratigraphically. This was interpreted as a single earlier population, T. imperator, speciating into more than one taxon, T. rex, and T. regina.

However, several other leading paleontologists, including Stephen Brusatte, Thomas Carr, Thomas Holtz, David Hone, Jingmai O'Connor, and Lindsay Zanno, criticized the study or expressed skepticism of its conclusions when approached by various media outlets for comment. Their criticism was subsequently published in a technical paper. Holtz and Zanno both remarked that it was plausible that more than one species of Tyrannosaurus existed, but felt the new study was insufficient to support the species it proposed. Holtz remarked that, even if Tyrannosaurus imperator represented a distinct species from Tyrannosaurus rex, it may represent the same species as Nanotyrannus lancensis and would need to be called Tyrannosaurus lancensis. O'Connor, a curator at the Field Museum, where the T. imperator holotype Sue is displayed, regarded the new species as too poorly supported to justify modifying the exhibit signs. Brusatte, Carr, and O'Connor viewed the distinguishing features proposed between the species as reflecting natural variation within a species. Both Carr and O'Connor expressed concerns about the study's inability to determine which of the proposed species several well-preserved specimens belonged to. Another paleontologist, Philip J. Currie, originally co-authored the study but withdrew from it as he did not want to be involved in naming the new species.

Paul rejected the objections raised by critics, insisting that they are unwilling to consider that Tyrannosaurus might represent more than one species. In a subsequent paper awaiting publication, Paul maintained the conclusion that Tyrannosaurus consists of three species. He pointed out that the criticism of the study naming T. imperator and T. regina only focused on two of the features used to distinguish the two new species (the number of small incisor teeth and femur robustness), while the original study also compared the robustness of other bones as well (the maxilla, dentary, humerus, ilium, and metatarsals). Furthermore, Paul argued that Tyrannosaurus can be separated into three different species based on the shape of knob-like bumps ('postorbital bosses') behind the eyes. Paul also argued that past research concluding that Tyrannosaurus only consists of one species (T. rex) has simply assumed that all Tyrannosaurus skeletons are a single species and that many new dinosaur species have been named based on fewer differences than he and his colleagues used when proposing T. imperator and T. regina.

Nanotyrannus: Other tyrannosaurid fossils found in the same formations as T. rex were originally classified as separate taxa, including Aublysodon and Albertosaurus megagracilis, the latter being named Dinotyrannus megagracilis in 1995. These fossils are now universally considered to belong to juvenile T. rex. A small but nearly complete skull from Montana, 60 centimeters (2.0 ft) long, might be an exception. This skull, CMNH 7541, was originally classified as a species of Gorgosaurus (G. lancensis) by Charles W. Gilmore in 1946. In 1988, the specimen was re-described by Robert T. Bakker, Phil Currie, and Michael Williams, then the curator of paleontology at the Cleveland Museum of Natural History, where the original specimen was housed and is now on display. Their initial research indicated that the skull bones were fused and that therefore represented an adult specimen. In light of this, Bakker and colleagues assigned the skull to a new genus named Nanotyrannus (meaning "dwarf tyrant", for its small adult size). The specimen is estimated to have been around 5.2 meters (17 ft) long when it died. However, In 1999, a detailed analysis by Thomas Carr revealed the specimen to be a juvenile, leading Carr and many other paleontologists to consider it a juvenile T. rex individual.

In 2001, a more complete juvenile tyrannosaur (nicknamed "Jane", catalog number BMRP 2002.4.1), belonging to the same species as the original Nanotyrannus specimen, was uncovered. This discovery prompted a conference on tyrannosaurs focused on the issues of Nanotyrannus validity at the Burpee Museum of Natural History in 2005. Several paleontologists who had previously published opinions that N. lancensis was a valid species, including Currie and Williams, saw the discovery of "Jane" as a confirmation that Nanotyrannus was, in fact, a juvenile T. rex. Peter Larson continued to support the hypothesis that N. lancensis was a separate but closely related species, based on skull features such as two more teeth in both jaws than T. rex; as well as proportionately larger hands with phalanges on the third metacarpal and different wishbone anatomy in an undescribed specimen. He also argued that Stygivenator, generally considered to be a juvenile T. rex, maybe a younger Nanotyrannus specimen. Later research revealed that other tyrannosaurids such as Gorgosaurus also experienced a reduction in tooth count during growth, and given the disparity in tooth count between individuals of the same age group in this genus and Tyrannosaurus, this feature may also be due to individual variation. In 2013, Carr noted that all of the differences claimed to support Nanotyrannus have turned out to be individually or ontogenetically variable features or products of distortion of the bones.

In 2016, an analysis of limb proportions by Persons and Currie suggested Nanotyrannus specimens have differing cursoriality levels, potentially separating it from T. rex. However, paleontologist Manabu Sakomoto has commented that this conclusion may be impacted by low sample size, and the discrepancy does not necessarily reflect taxonomic distinction. In 2016, Joshua Schmerge argued for Nanotyrannus' validity based on skull features, including a dentary groove in BMRP 2002.4.1's skull. According to Schmerge, as that feature is absent in T. rex and found only in Dryptosaurus and Albertosaurines, this suggests that Nanotyrannus is a distinct taxon within the Albertosaurinae. The same year, Carr and colleagues noted that this was not sufficient enough to clarify Nanotyrannus' validity or classification, being a common and ontogenetically variable feature among tyrannosauroids.

A 2020 study by Holly Woodward and colleagues showed the specimens referred to Nanotyrannus were all ontogenetically immature and found it probable that these specimens belonged to T. rex. The same year, Carr published a paper on T. rex's growth history, finding that CMNH 7541 fit within the expected ontogenetic variation of the taxon and displayed juvenile characteristics found in other specimens. It was classified as a juvenile, under 13 years old with a skull less than 80 cm (31 in). No significant sexual or phylogenetic variation was discernible among any of the 44 specimens studied, with Carr stating that characters of potential phylogenetic importance decrease throughout age at the same rate as growth occurs. Discussing the paper's results, Carr described how all "Nanotyrannus'' specimens formed a continual growth transition between the smallest juveniles and the subadults, unlike what would be expected if it were a distinct taxon where the specimens would group to the exclusion of Tyrannosaurus. Carr concluded that "the 'nano-morphs' are not all that similar to each other and instead form an important bridge in the growth series of T. rex that captures the beginnings of the profound change from the shallow skull of juveniles to the deep skull that is seen in fully-developed adults."

We have only observed adolescent and young adult specimens, our plan is once the T. Rexes breed in our park and during a time when we go back to find mates for Terrence and Matilda. We will observe the offspring by watching their development and hoping they'll reach a life stage that resembles Nanotyrannus along with DNA Tests to prove that Tyrannosaurus and Nanotyrannus are the same species.

Paleobiology

Life History: The identification of several specimens as juvenile T. rex has allowed scientists to document ontogenetic changes in the species, estimate the lifespan, and determine how quickly the animals would have grown. The smallest known individual (LACM 28471, the "Jordan theropod") is estimated to have weighed only 30 kg (66 lb), while the largest, such as FMNH PR2081 (Sue) most likely weighed about 5,650 kg (12,460 lb). Histologic analysis of T. rex bones showed LACM 28471 had aged only 2 years when it died, while Sue was 28 years old, an age which may have been close to the maximum for the species.

Histology has also allowed the age of other specimens to be determined. Growth curves can be developed when the ages of different specimens are plotted on a graph along with their mass. A T. rex growth curve is S-shaped, with juveniles remaining under 1,800 kg (4,000 lb) until approximately 14 years of age when body size begins to increase dramatically. During this rapid growth phase, a young T. rex would gain an average of 600 kg (1,300 lb) a year for the next four years. At 18 years of age, the curve plateaus again, indicating that growth slowed dramatically. For example, only 600 kg (1,300 lb) separated the 28-year-old Sue from a 22-year-old Canadian specimen (RTMP 81.12.1). A 2004 histological study performed by different workers corroborates these results, finding that rapid growth began to slow at around 16 years of age.

A study by Hutchinson and colleagues in 2011 corroborated the previous estimation methods in general, but their estimation of peak growth rates is significantly higher; it found that the "maximum growth rates for T. rex during the exponential stage are 1790 kg/year". Although these results were much higher than previous estimations, the authors noted that these results significantly lowered the great difference between its actual growth rate and the one that would be expected of an animal of its size. The sudden change in growth rate at the end of the growth spurt may indicate physical maturity, a hypothesis which is supported by the discovery of medullary tissue in the femur of a 16 to 20-year-old T. rex from Montana (MOR 1125, also known as B-rex). Medullary tissue is found only in female birds during ovulation, indicating that B-rex was of reproductive age. Further study indicates an age of 18 for this specimen. In 2016, it was finally confirmed by Mary Higby Schweitzer and Lindsay Zanno and colleagues that the soft tissue within the femur of MOR 1125 was medullary tissue. This also confirmed the identity of the specimen as a female. The discovery of medullary bone tissue within Tyrannosaurus may prove valuable in determining the sex of other dinosaur species in future examinations, as the chemical makeup of medullary tissue is unmistakable. Other tyrannosaurids exhibit extremely similar growth curves, although with lower growth rates corresponding to their lower adult sizes.

An additional study published in 2020 by Woodward and colleagues, for the journal Science Advances, indicates that during their growth from juvenile to adult, Tyrannosaurus was capable of slowing down its growth to counter environmental factors such as lack of food. The study, focusing on two juvenile specimens between 13 and 15 years old housed at the Burpee Museum in Illinois, indicates that the rate of maturation for Tyrannosaurus was dependent on resource abundance. This study also indicates that in such changing environments, Tyrannosaurus was particularly well-suited to an environment that shifted yearly in regards to resource abundance, hinting that other midsize predators might have had difficulty surviving in such harsh conditions and explaining the niche partitioning between juvenile and adult tyrannosaurs. The study further indicates that Tyrannosaurus and the dubious genus Nanotyrannus are synonymous, due to analysis of the growth rings in the bones of the two specimens studied.

Over half of the known T. rex specimens appear to have died within six years of reaching sexual maturity, a pattern which is also seen in other tyrannosaurs and some large, long-lived birds and mammals today. These species are characterized by high infant mortality rates, followed by relatively low mortality among juveniles. Mortality increases again following sexual maturity, partly due to the stresses of reproduction. One study suggests that the rarity of juvenile T. rex fossils is due in part to low juvenile mortality rates; the animals were not dying in large numbers at these ages, and thus were not often fossilized. This rarity may also be due to the incompleteness of the fossil record or to the bias of fossil collectors towards larger, more spectacular specimens. In a 2013 lecture, Thomas Holtz Jr. suggested that dinosaurs "lived fast and died young" because they reproduced quickly whereas mammals have long life spans because they take longer to reproduce. Gregory S. Paul also writes that Tyrannosaurus reproduced quickly and died young, but attributes their short life spans to the dangerous lives they lived.

Although perhaps a few individuals would reach to ages of 42-50 years old in the wild, T. Rex would have had a longer lifespan in captivity.

Skin and possible filamentous feathering: The discovery of feathered dinosaurs led to debate regarding whether, and to what extent, Tyrannosaurus might have been feathered. Filamentous structures, which are commonly recognized as the precursors of feathers, have been reported in the small-bodied, basal tyrannosauroid Dilong paradoxus from the Early Cretaceous Yixian Formation of China in 2004. Because integumentary impressions of larger tyrannosauroids known at that time showed evidence of scales, the researchers who studied Dilong speculated that insulating feathers might have been lost by larger species due to their smaller surface-to-volume ratio. The subsequent discovery of the giant species Yutyrannus huali, also from the Yixian, showed that even some large tyrannosauroids had feathers covering much of their bodies, casting doubt on the hypothesis that they were a size-related feature. A 2017 study reviewed known skin impressions of tyrannosaurids, including those of a Tyrannosaurus specimen nicknamed "Wyrex" (BHI 6230) which preserves patches of mosaic scales on the tail, hip, and neck. The study concluded that feather covering of large tyrannosaurids such as Tyrannosaurus was, if present, limited to the upper side of the trunk.

A conference abstract published in 2016 posited that theropods such as Tyrannosaurus had their upper teeth covered in lips, instead of bare teeth as seen in crocodilians. This was based on the presence of enamel, which according to the study needs to remain hydrated, an issue not faced by aquatic animals like crocodilians. However, there has been criticism that favors the idea of lips, with the 2017 analytical study proposing that tyrannosaurids had large, flat scales on their snouts instead of lips just like modern crocodiles. But crocodiles possess rather cracked keratinized skin, not flat scales; by observing the hummocky rugosity of tyrannosaurids, and comparing it to extant lizards, researchers have found that tyrannosaurids had squamose scales rather than crocodilian-like skin.

In 2023, Cullen and colleagues supported the idea that theropods like tyrannosaurids had lips based on anatomical patterns, such as those of the foramina on their face and jaws, more similar to those of modern squamates such as monitor lizards or marine iguanas than those of modern crocodilians like alligators. By comparatively analyzing the dentition of Daspletosaurus and the American alligator, it was shown that the enamel of tyrannosaurids had no significant wear, while that of modern crocodilians had erosion on the labial side and substantial wear. This suggests that it is likely that theropod teeth existed under hydrated conditions (i.e. extraoral tissues). Based on the relationship between hydration and wear resistance, the authors argued that it is unlikely that the teeth of theropods including tyrannosaurids would have remained unworn when exposed for a long time, as it would have been difficult to maintain hydration. The authors also performed regression analyses to demonstrate the relationship between tooth height and skull length and found that varanids like the crocodile monitor had substantially greater tooth height–to–skull length ratios than Tyrannosaurus, indicating that the teeth of theropods were not too big to be covered by extraoral tissues when the mouth was closed.

When our team first encountered the T. rex, unlike many depictions in popular culture, their teeth were covered in scaly lips instead of exposed teeth. The adults were covered in scales with bristle filament peach fuzz around the top, shoulder, and arm regions of their body while adolescents had a mane of downy feathering around the neck, head, and arms which later molt as they grew up.

There is a comparison sketch of the Jurassic Park/World T. Rex and the more Scientifically Accurate T. Rex.

Sexual Dimorphism: As the number of known specimens increased, scientists began to analyze the variation between individuals and discovered what appeared to be two distinct body types, or morphs, similar to some other theropod species. As one of these morphs was more solidly built, it was termed the 'robust' morph while the other was termed 'gracile'. Several morphological differences associated with the two morphs were used to analyze sexual dimorphism in T. rex, with the 'robust' morph usually suggested to be female. For example, the pelvis of several 'robust' specimens seemed to be wider, perhaps to allow the passage of eggs. It was also thought that the 'robust' morphology correlated with a reduced chevron on the first tail vertebra, also ostensibly to allow eggs to pass out of the reproductive tract, as had been erroneously reported for crocodiles.

When observing the adult T. Rexes including the Park Resident Mating pair: Tyrannor and Rexy. We noticed that Males are larger in weight and length while Females are Taller. The Male was more colorful around the head, neck, and throat as it had longer bigger thin black bristle manes, a mottled face mixed of yellow-orange and dark brown stripes and blotches, red patches on each side that went down the neck, a red gular sac throat, and bumpy keratin running down its nose, orbital hornlets, and brow which was bright orange more pronounced in its large size and horn-like. The Females have a short bristle mane and a peach-mottled face with dark brown spots and stripes and the keratin ran down its nose, orbital hornlets, and brow which was light orange.

Posture: Like many bipedal dinosaurs, T. rex was historically depicted as a 'living tripod', with the body at 45 degrees or less from the vertical and the tail dragging along the ground, similar to a kangaroo. This concept dates from Joseph Leidy's 1865 reconstruction of Hadrosaurus, the first to depict a dinosaur in a bipedal posture. In 1915, convinced that the creature stood upright, Henry Fairfield Osborn, former president of the American Museum of Natural History, further reinforced the notion by unveiling the first complete T. rex skeleton arranged this way. It stood in an upright pose for 77 years, until it was dismantled in 1992.

Numbuh 2 sketched the moment he, Numbuh 4, Danny, Gerald, Arnold, Mallow, and Charlie escaped Tyrannor as the T. Rex rammed the tree and they slide down his back and tail, Flintstones Style with the two operative boys shouting "Yabba Dabba Doo!."

By 1970, scientists realized this pose was incorrect and could not have been maintained by a living animal, as it would have resulted in the dislocation or weakening of several joints, including the hips and the articulation between the head and the spinal column. The inaccurate AMNH mount inspired similar depictions in many films and paintings (such as Rudolph Zallinger's famous mural The Age of Reptiles in Yale University's Peabody Museum of Natural History) until the 1990s when films such as Jurassic Park introduced a more accurate posture to the general public. Modern representations in museums, art, and film show T. rex with its body approximately parallel to the ground with the tail extended behind the body to balance the head.

To sit down, Tyrannosaurus may have settled its weight backward and rested its weight on a pubic boot, the wide expansion at the end of the pubis in some dinosaurs. With its weight resting on the pelvis, it may have been free to move the hindlimbs. Getting back up again might have involved some stabilization from the diminutive forelimbs. The latter known as Newman's pushup theory has been debated. Nonetheless, Tyrannosaurus was probably able to get up if it fell, which only would have required placing the limbs below the center of gravity, with the tail as an effective counterbalance. Healed stress fractures in the forelimbs have been put forward both as evidence that the arms cannot have been very useful and as evidence that they were indeed used and acquired wounds, like the rest of the body.

Tyrannosaurs like all animals must sleep and there is fossil evidence of dinosaurs found in sleeping postures similar to birds. The postures include sleeping on their sides, resting on their bellies, or sleeping with their tails curved. They normally sleep 3-8 hours a day.

Arms: Tyrannosaurus Rex had small arms by dinosaur standards, but that is because they evolved to have a devastating bone-crunching bite. If Tyrannosaurs had survived past the Cretaceous extinction event and the volcanic atmosphere that was killing the dinosaurs off before the asteroid hit, they might have lost their arms altogether. Despite their arms being relatively small, they were still powerful and were the size of an adult human's arm.

Paleontologist Kevin Padian argued that the reduction of the arms in tyrannosaurids did not serve a particular function but was a secondary adaptation, stating that as tyrannosaurids developed larger and more powerful skulls and jaws, the arms got smaller to avoid being bitten or torn by other individuals, particularly during group feedings.

Another possibility is that the forelimbs held struggling prey while it was killed by the tyrannosaur's enormous jaws. This hypothesis may be supported by biomechanical analysis. T. rex forelimb bones exhibit extremely thick cortical bone, which has been interpreted as evidence that they were developed to withstand heavy loads. The biceps brachii muscle of an adult T. rex was capable of lifting 199 kilograms (439 lb) by itself; other muscles such as the brachialis would work along with the biceps to make elbow flexion even more powerful.

The idea that the arms served as weapons when hunting prey has also been proposed by Steven M. Stanley, who suggested that the arms were used for slashing prey, especially by using the claws to rapidly inflict long, deep gashes on its prey. This was dismissed by Padian, who argued that Stanley based his conclusion on incorrectly estimated forelimb size and range of motion.

Tyrannosaurus could have used its arms to grasp a hold of their prey, an object, and possibly carry their young.

"Eddy doodled himself, and Ed laughing at the T. Rex's arms in which the theropod is very angry at them, and wants to eat them while Double D looks on in a worried state."

Thermoregulation: Tyrannosaurus, like most dinosaurs, was long thought to have an ectothermic ("cold-blooded") reptilian metabolism. The idea of dinosaur ectothermy was challenged by scientists like Robert T. Bakker and John Ostrom in the early years of the "Dinosaur Renaissance", beginning in the late 1960s. T. rex itself was claimed to have been endothermic ("warm-blooded"), implying a very active lifestyle. Since then, several paleontologists have sought to determine the ability of Tyrannosaurus to regulate its body temperature. Histological evidence of high growth rates in young T. rex, comparable to those of mammals and birds, may support the hypothesis of high metabolism. Growth curves indicate that, as in mammals and birds, T. rex growth was limited mostly to immature animals, rather than the indeterminate growth seen in most other vertebrates.

Oxygen isotope ratios in fossilized bone are sometimes used to determine the temperature at which the bone was deposited, as the ratio between certain isotopes correlates with temperature. In one specimen, the isotope ratios in bones from different parts of the body indicated a temperature difference of no more than 4 to 5 °C (7 to 9 °F) between the vertebrae of the torso and the tibia of the lower leg. This small temperature range between the body core and the extremities was claimed by paleontologist Reese Barrick and geochemist William Showers to indicate that T. rex maintained a constant internal body temperature (homeothermy) and that it enjoyed a metabolism somewhere between ectothermic reptiles and endothermic mammals. Other scientists have pointed out that the ratio of oxygen isotopes in the fossils today does not necessarily represent the same ratio in the distant past, and may have been altered during or after fossilization (diagenesis). Barrick and Showers have defended their conclusions in subsequent papers, finding similar results in another theropod dinosaur from a different continent and tens of millions of years earlier in time (Giganotosaurus). Ornithischian dinosaurs also showed evidence of homeothermy, while varanid lizards from the same formation did not. In 2022, Wiemann and colleagues used a different approach—the spectroscopy of lipoxidation signals, which are byproducts of oxidative phosphorylation and correlate with metabolic rates—to show that various dinosaur genera including Tyrannosaurus had endothermic metabolisms, on par with that of modern birds and higher than that of mammals. They also suggested that such a metabolism was ancestrally common to all dinosaurs.

Even if T. rex does exhibit evidence of homeothermy, it does not necessarily mean that it was endothermic. Such thermoregulation may also be explained by gigantothermy, as in some living sea turtles. Similar to contemporary crocodilians, openings (dorsotemporal fenestrae) in the skull roofs of Tyrannosaurus may have aided thermoregulation.

To keep themselves cool, Tyrannosaurus would rest in the shade of trees or caves, they would wallow in shallow lakes, ponds, and rivers, and dust bath and wallow in mud to protect themselves from the sun and get rid of parasites

Soft Tissue: In the March 2005 issue of Science, Mary Higby Schweitzer of North Carolina State University and colleagues announced the recovery of soft tissue from the marrow cavity of a fossilized leg bone from a T. rex. The bone had been intentionally, though reluctantly, broken for shipping and then not preserved in the normal manner, specifically because Schweitzer was hoping to test it for soft tissue. Designated as the Museum of the Rockies specimen 1125, or MOR 1125, the dinosaur was previously excavated from the Hell Creek Formation. Flexible, bifurcating blood vessels and fibrous but elastic bone matrix tissue were recognized. In addition, microstructures resembling blood cells were found inside the matrix and vessels. The structures bear a resemblance to ostrich blood cells and vessels. Whether an unknown process, distinct from normal fossilization, preserved the material, or the material is original, the researchers do not know, and they are careful not to make any claims about preservation. If it is found to be original material, any surviving proteins may be used as a means of indirectly guessing some of the DNA content of the dinosaurs involved, because each protein is typically created by a specific gene. The absence of previous findings may be the result of people assuming preserved tissue was impossible, therefore not looking. Since the first, two more tyrannosaurs and a hadrosaur have also been found to have such tissue-like structures. Research on some of the tissues involved has suggested that birds are closer relatives to tyrannosaurs than other modern animals.

In studies reported in Science in April 2007, Asara and colleagues concluded that seven traces of collagen proteins detected in a purified T. rex bone most closely match those reported in chickens, followed by frogs and newts. The discovery of proteins from a creature tens of millions of years old, along with similar traces the team found in a mastodon bone at least 160,000 years old, upends the conventional view of fossils and may shift paleontologists' focus from bone hunting to biochemistry. Until these findings, most scientists presumed that fossilization replaced all living tissue with inert minerals. Paleontologist Hans Larsson of McGill University in Montreal, who was not part of the studies, called the findings "a milestone", and suggested that dinosaurs could "enter the field of molecular biology and slingshot paleontology into the modern world".

The presumed soft tissue was called into question by Thomas Kaye of the University of Washington and his co-authors in 2008. They contend that what was really inside the tyrannosaur bone was a slimy biofilm created by bacteria that coated the voids once occupied by blood vessels and cells. The researchers found that what previously had been identified as remnants of blood cells, because of the presence of iron, were framboids, microscopic mineral spheres bearing iron. They found similar spheres in a variety of other fossils from various periods, including an ammonite. In the ammonite, they found the spheres in a place where the iron they contained could not have had any relationship to the presence of blood. Schweitzer has strongly criticized Kaye's claims and argues that there is no reported evidence that biofilms can produce branching, hollow tubes like those noted in her study. San Antonio, Schweitzer, and colleagues published an analysis in 2011 of what parts of the collagen had been recovered, finding that it was the inner parts of the collagen coil that had been preserved, as would have been expected from a long period of protein degradation. Other research challenges the identification of soft tissue as biofilm and confirms finding "branching, vessel-like structures" from within fossilized bone.

Speed: Unlike the movie depiction of a T. Rex running at 32 miles per hour even chasing a jeep, This has been disproven with the latest scientific evidence that it wasn't a fast runner due to its large size, and its body anatomy wasn't built for speed.

"Sid doodled a sketch of Thomas, Charlie, and her mom Becca on a jeep being chased by Matilda although she is way behind the group."

Another depiction is when the T. Rex places one foot in front of the other creating a stomping sound this was only done for dramatic effects. In Real life, stomping will give the predator away and the prey will run away, T. Rex was a silent hunter and their feet have fleshy pads that cushion it when it places its foot on the ground making it even more dangerous.

Scientists have produced a wide range of possible maximum running speeds for Tyrannosaurus: mostly around 9 meters per second (32 km/h; 20 mph), but as low as 4.5–6.8 meters per second (16–24 km/h; 10–15 mph) and as high as 20 meters per second (72 km/h; 45 mph), though it running this speed is very unlikely. Tyrannosaurus was a bulky and heavy carnivore so it is unlikely to run very fast at all compared to other theropods like Carnotaurus or Giganotosaurus. Researchers have relied on various estimating techniques because, while there are many tracks of large theropods walking, none showed evidence of running.

A 2002 report used a mathematical model (validated by applying it to three living animals: alligators, chickens, and humans; and eight more species, including emus and ostriches) to gauge the leg muscle mass needed for fast running (over 40 km/h or 25 mph). Scientists who think that Tyrannosaurus was able to run point out that hollow bones and other features that would have lightened its body may have kept adult weight to a mere 4.5 metric tons (5.0 short tons) or so, or that other animals like ostriches and horses with long, flexible legs can achieve high speeds through slower but longer strides. Proposed top speeds exceeded 40 kilometers per hour (25 mph) for Tyrannosaurus, but were deemed infeasible because they would require exceptional leg muscles of approximately 40–86% of total body mass. Even moderately fast speeds would have required large leg muscles. If the muscle mass was less, only 18 kilometers per hour (11 mph) for walking or jogging would have been possible. Holtz noted that tyrannosaurids and some closely related groups had significantly longer distal hindlimb components (shin plus foot plus toes) relative to the femur length than most other theropods and that tyrannosaurids and their close relatives had tightly interlocked metatarsus (foot bones). The third metatarsal was squeezed between the second and fourth metatarsals to form a single unit called an arctometatarsus. This ankle feature may have helped the animal to run more efficiently. Together, these leg features allowed Tyrannosaurus to transmit locomotory forces from the foot to the lower leg more effectively than in earlier theropods.

Additionally, a 2020 study indicates that Tyrannosaurus and other tyrannosaurids were exceptionally efficient walkers. Studies by Dececchi et al., compared the leg proportions, body mass, and gaits of more than 70 species of theropod dinosaurs including Tyrannosaurus and its relatives. The research team then applied a variety of methods to estimate each dinosaur's top speed when running as well as how much energy each dinosaur expended while moving at more relaxed speeds such as when walking. Among smaller to medium-sized species such as dromaeosaurids, longer legs appear to be an adaptation for faster running, in line with previous results by other researchers. But for theropods weighing over 1,000 kg (2,200 lb), top running speed is limited by body size, so longer legs instead were found to have correlated with low-energy walking. The results further indicate that smaller theropods evolved long legs as a means to both aid in hunting and escape from larger predators while larger theropods that evolved long legs did so to reduce the energy costs and increase foraging efficiency, as they were freed from the demands of predation pressure due to their role as apex predators. Compared to more basal groups of theropods in the study, tyrannosaurs like Tyrannosaurus itself showed a marked increase in foraging efficiency due to reduced energy expenditures during hunting or scavenging. This in turn likely resulted in tyrannosaurs having a reduced need for hunting forays and requiring less food to sustain themselves as a result. Additionally, the research, in conjunction with studies that show tyrannosaurs were more agile than other large-bodied theropods, indicates they were quite well-adapted to a long-distance stalking approach followed by a quick burst of speed to go for the kill. Analogies can be noted between tyrannosaurids and modern wolves as a result, supported by evidence that at least some tyrannosaurids were hunting in group settings.

A study published in 2021 by Pasha van Bijlert et al., calculated the preferred walking speed of Tyrannosaurus, reporting a speed of 1.28 meters per second (4.6 km/h; 2.9 mph). While walking, animals reduce their energy expenditure by choosing certain step rhythms at which their body parts resonate. The same would have been true for dinosaurs, but previous studies did not fully account for the impact the tail had on their walking speeds. According to the authors, when a dinosaur walked, its tail would slightly sway up and down with each step as a result of the interspinous ligaments suspending the tail. Like rubber bands, these ligaments store energy when they are stretched due to the swaying of the tail. Using a 3-D model of Tyrannosaurus specimen Trix, muscles and ligaments were reconstructed to simulate the tail movements. This results in a rhythmic, energy-efficient walking speed for Tyrannosaurus similar to that seen in living animals such as humans, ostriches, and giraffes.

A 2017 study estimated the top running speed of Tyrannosaurus as 17 mph (27 km/h), speculating that Tyrannosaurus exhausted its energy reserves long before reaching top speed, resulting in a parabola-like relationship between size and speed. Another 2017 study hypothesized that an adult Tyrannosaurus was incapable of running due to high skeletal loads. Using a calculated weight estimate of 7 tons, the model showed that speeds above 11 mph (18 km/h) would have probably shattered the leg bones of Tyrannosaurus. The finding may mean that running was also not possible for other giant theropod dinosaurs like Giganotosaurus, Mapusaurus, and Acrocanthosaurus. However, studies by Eric Snively and colleagues, published in 2019 indicate that Tyrannosaurus and other tyrannosaurids were more maneuverable than allosauroids and other theropods of comparable size due to low rotational inertia compared to their body mass combined with large leg muscles. As a result, it is hypothesized that Tyrannosaurus was capable of making relatively quick turns and could likely pivot its body more quickly when close to its prey, or that while turning, the theropod could "pirouette" on a single planted foot while the alternating leg was held out in a suspended swing during a pursuit. The results of this study potentially could shed light on how agility could have contributed to the success of tyrannosaurid evolution.

Swimming: There have been observations of Tyrannosaurus swimming both in the wild in oceans and deep lakes and in captivity at the park in their paddock lake. Even with its bulk, Tyrannosaurus was a capable swimmer based on its muscular build and weight-saving adaptations, although it didn't have any specific aquatic adaptations, neither do a lot of extant swimming amniotes. Many large animals can swim like elephants, reindeer, lions, and emus. We have fossil evidence of trace fossil scrap marks made by dinosaurs scraping the water-sediment floor as they swam. The T. Rex depends on its bulky and air sac body for buoyancy, long tail for balance and a rudder, long legs with large feet to paddle, and keeping its head up to breathe and occasionally deep breaths to look underwater in case of danger from marine predators like mosasaurs.

Possible Footprints: Rare fossil footprints and trackways found in New Mexico and Wyoming that are assigned to the ichnogenus Tyrannosauripus have been attributed to being made by Tyrannosaurus, based on the stratigraphic age of the rocks they are preserved in. The first specimen, found in 1994 was described by Lockley and Hunt and consists of a single, large footprint. Another pair of ichnofossils, described in 2021, show a large tyrannosaurid rising from a prone position by using its elbows in conjunction with the pads on its feet to stand. These two unique sets of fossils were found in Ludlow, Colorado, and Cimarron, New Mexico. Another ichnofossil described in 2018, perhaps belonging to a juvenile Tyrannosaurus or the dubious genus Nanotyrannus was uncovered in the Lance Formation of Wyoming. The trackway itself offers a rare glimpse into the walking speed of tyrannosaurids, and the trackmaker is estimated to have been moving at a speed of 4.5–8.0 kilometers per hour (2.8–5.0 mph), significantly faster than previously assumed for estimations of walking speed in tyrannosaurids.

Brains and Senses: Although it is known for its sense of smell, the strategy is if you stand still the T. Rex won't see if you don't move, in truth, the T. Rex will still see you and will eat you alive, unlike most popularized depictions which was the result of manipulation of their genes with reed frog DNA which the poor sense of sight came from genetically. Also, it turns out that T. Rex was not as dumb as in most depictions, but they were thinking and intelligent dinosaurs.

Tyrannosaurus has forward-facing eyes giving it excellent binocular vision and remarkable night vision, making it a fearsome predator in any environment. However, in 2021, a comparison with the alvarezsaur Shuvuuia suggested that T. rex and Dromaeosaurus primarily hunted during the daytime.

While an animal cannot be both completely diurnal or nocturnal at the same time given the contradictory nature of both forms of behavior, a possible compromise for both of these ideas is that T. rex was neither fully diurnal or nocturnal, but cathemeral, active at irregular intervals throughout the day, much like lions.

As a sight-reliant predator, the eyes of Tyrannosaurus are of utmost importance to it. Hence, when a fight is not worth the legitimate threat of losing sight completely (especially when it has lost sight in one eye due to prior experience), it would prioritize keeping its remaining means of sight intact.

A study conducted by Lawrence Witmer and Ryan Ridgely of Ohio University found that Tyrannosaurus shared the heightened sensory abilities of other coelurosaurs, highlighting relatively rapid and coordinated eye and head movements; an enhanced ability to sense low-frequency sounds, which would allow tyrannosaurs to track prey movements from long distances; and an enhanced sense of smell. A study published by Kent Stevens concluded that Tyrannosaurus had a keen vision. By applying modified perimetry to facial reconstructions of several dinosaurs including Tyrannosaurus, the study found that Tyrannosaurus had a binocular range of 55 degrees, surpassing that of modern hawks. Stevens estimated that Tyrannosaurus had 13 times the visual acuity of a human and surpassed the visual acuity of an eagle, which is 3.6 times that of a person. Stevens estimated a limiting far point (that is, the distance at which an object can be seen as separate from the horizon) as far as 6 km (3.7 mi) away, which is greater than the 1.6 km (1 mi) that a human can see.

Thomas Holtz Jr. would note that high depth perception of Tyrannosaurus may have been due to the prey it had to hunt, noting that it had to hunt ceratopsians such as Triceratops, ankylosaurs such as Ankylosaurus, and hadrosaurs. He would suggest that this made precision more crucial for Tyrannosaurus enabling it to, "get in, get that blow in, and take it down." In contrast, Acrocanthosaurus had limited depth perception because they hunted large sauropods, which were relatively rare during the time of Tyrannosaurus.

Tyrannosaurus had very large olfactory bulbs and olfactory nerves relative to their brain size, the organs responsible for a heightened sense of smell. This suggests that the sense of smell was highly developed, and implies that tyrannosaurs could detect carcasses by scent alone across great distances. The sense of smell in tyrannosaurs may have been comparable to modern vultures, which use scent to track carcasses for scavenging. Research on the olfactory bulbs has shown that T. rex had the most highly developed sense of smell of 21 sampled non-avian dinosaur species.

Somewhat unusually among theropods, T. rex had a very long cochlea. The length of the cochlea is often related to hearing acuity, or at least the importance of hearing in behavior, implying that hearing was a particularly important sense to tyrannosaurs. Specifically, data suggests that T. rex heard best in the low-frequency range, and that low-frequency sounds were an important part of tyrannosaur behavior. A 2017 study by Thomas Carr and colleagues found that the snout of tyrannosaurids was highly sensitive, based on many small openings in the facial bones of the related Daspletosaurus that contained sensory neurons. The study speculated that tyrannosaurs might have used their sensitive snouts to measure the temperature of their nests and to gently pick up eggs and hatchlings, as seen in modern crocodilians. Another study published in 2021 further suggests that Tyrannosaurus had an acute sense of touch, based on neurovascular canals in the front of its jaws, which it could utilize to better detect and consume prey. The study, published by Kawabe and Hittori et al., suggests that Tyrannosaurus could also accurately sense slight differences in material and movement, allowing it to utilize different feeding strategies on different parts of its prey's carcasses depending on the situation. The sensitive neurovascular canals of Tyrannosaurus also likely were adapted to performing fine movements and behaviors such as nest building, parental care, and other social behavior such as intraspecific communication. The results of this study also align with results made in studying the related tyrannosaurid Daspletosaurus horneri and the allosauroid Neovenator, which have similar neurovascular adaptations, suggesting that the faces of theropods were highly sensitive to pressure and touch. However, a more recent study reviewing the evolution of the trigeminal canals among sauropsids notes that a much denser network of neurovascular canals in the snout and lower jaw is more commonly encountered in aquatic or semi-aquatic taxa (e.g., Spinosaurus, Halszkaraptor, Plesiosaurus), and taxa that developed a rhamphotheca (e.g., Caenagnathasia), while the network of canals in Tyrannosaurus appears simpler, though still more derived than in most ornithischians, and overall terrestrial taxa such as tyrannosaurids and Neovenator may have had average facial sensitivity for non-edentulous terrestrial theropods, although further research is needed. The neurovascular canals in Tyrannosaurus may instead have supported soft tissue structures for thermoregulation or social signaling, the latter of which could be confirmed by the fact that the neurovascular network of canals may have changed during ontogeny.

A study by Grant R. Hurlburt, Ryan C. Ridgely, and Lawrence Witmer obtained estimates for Encephalization Quotients (EQs), based on reptiles and birds, as well as estimates for the ratio of cerebrum to brain mass. The study concluded that Tyrannosaurus had the relatively largest brain of all adult non-avian dinosaurs except for certain small maniraptoriforms (Bambiraptor, Troodon, and Ornithomimus). The study found that Tyrannosaurus's relative brain size was still within the range of modern reptiles, being at most 2 standard deviations above the mean of non-avian reptile EQs. The estimates for the ratio of cerebrum mass to brain mass would range from 47.5 to 49.53 percent. According to the study, this is more than the lowest estimates for extant birds (44.6 percent) but still close to the typical ratios of the smallest sexually mature alligators which range from 45.9 - 47.9 percent. Other studies, such as those by Steve Brusatte, indicate the encephalization quotient of Tyrannosaurus was similar in range (2.0–2.4) to a chimpanzee (2.2–2.5), though this may be debatable as reptilian and mammalian encephalization quotients are not equivalent.

It is believed that because of their large brains and recent studies show that T. Rex had the same number of brain neurons as modern primates like Baboon and may have been capable of problem-solving and even culture. Dinosaurs would have had a similar brain mass to birds of the same size that can be traced back to pre-asteroid times. Birds like corvids including crows and jays are intelligent despite their small heads and size. Birds have been found to have more neurons per ounce of the brain compared to mammals and primates, giving them the ability to solve problems. For Example, Eurasian jays can resist the temptation to get a better reward, while crows have been described as being as smart as seven-year-olds.

Based on a recent study examining the skulls of T. Rex and other dinosaurs via CT Scans, T. Rex would have had a brain mass of 343 grams and 3,289,000,000 telencephalic neurons, not far from the 2,875,000,000 found in baboons. Another study found that the number of neurons in warm-blooded animals correlates to their life expectancy by a mathematical equation.

The Current T. Rex Pack is currently being studied. Perhaps these theropods have the biological capability to use and craft tools and develop a culture, like modern birds and primates. We might observe new social behaviors or abilities never before seen for now, we will sit back and watch them until they are ready to reveal their secrets.

Family Lifestyle/Social Behavior: Philip J. Currie suggested that Tyrannosaurus may have been pack hunters, comparing T. rex to related species Tarbosaurus bataar and Albertosaurus sarcophagus, citing fossil evidence that may indicate gregarious (describing animals that travel in herds or packs) behavior. A find in South Dakota where three T. rex skeletons were nearby may suggest the formation of a pack. Cooperative pack hunting may have been an effective strategy for subduing prey with advanced anti-predator adaptations which pose potential lethality such as Triceratops and Ankylosaurus.

Currie's pack-hunting T. rex hypothesis has been criticized for not having been peer-reviewed but rather was discussed in a television interview and book called Dino Gangs. The Currie theory for pack hunting by T. rex is based mainly on an analogy to a different species, Tarbosaurus bataar. Evidence of gregariousness in T bataar itself has not been peer-reviewed, and to Currie's admission, can only be interpreted regarding evidence in other closely related species. According to Currie gregariousness in Albertosaurus sarcophagus is supported by the discovery of 26 individuals with varied ages in the Dry Island bone bed. He ruled out the possibility of a predator trap due to the similar preservation state of individuals and the near absence of herbivores.

Additional support of tyrannosaurid gregariousness can be found in fossilized trackways from the Upper Cretaceous Wapiti Formation of northeastern British Columbia, Canada, left by three tyrannosaurids traveling in the same direction. According to scientists assessing the Dino Gangs program, the evidence for pack hunting in Tarbosaurus and Albertosaurus is weak and based on group skeletal remains for which alternate explanations may apply (such as drought or a flood forcing dinosaurs to die together in one place). Other researchers have speculated that instead of large theropod social groups, some of these finds represent behavior more akin to Komodo dragon-like mobbing of carcasses, even going as far as to say true pack-hunting behavior may not exist in any non-avian dinosaurs due to its rarity in modern predators.

Evidence of an intraspecific attack was found by Joseph Peterson and his colleagues in the juvenile Tyrannosaurus nicknamed Jane. Peterson and his team found that Jane's skull showed healed puncture wounds on the upper jaw and snout which they believe came from another juvenile Tyrannosaurus. Subsequent CT scans of Jane's skull would further confirm the team's hypothesis, showing that the puncture wounds came from a traumatic injury and that there was subsequent healing. The team would also state that Jane's injuries were structurally different from the parasite-induced lesions found in Sue and that Jane's injuries were on its face whereas the parasite that infected Sue caused lesions to the lower jaw.

Based on our findings, Tyrannosaurus Rex lived alone or in loosely formed family packs led by a Mater pair and their offspring. Sub-adults who are kicked out or leave their family groups form loosely-knitted sibling groups before parting ways. Some juveniles would join loosely-knitted coalition packs.

Diet: Tyrannosaurus Rex were found all around North America and were the apex predators of their time controlling the populations of Herbivores of their environment both hunter and scavenger preying upon Hadrosaurs (Edmontosaurus), armored Herbivores like ceratopsians (Triceratops, Leptoceratops, and Torosaurus), and Ankylosaurs (Ankylosaurus and Denversaurus), and possibly pterosaurs (Quetzalcoatlus), sauropods (Alamosaurus) and washed up marine reptiles and giant sea turtles,

Other predators like Dakotaraptor, Pectinodon, Acheroraptor, and Dromaeosaurus even if killed are ignored as eating other carnivores can be life-threatening and could carry diseases.

Smaller prey includes smaller dinosaurs like Ornithomimus, Anzu, Pachycephalosaurus, and Thescelosaurus, and in rare cases, fishes like Melvius, Paleopsephurus, Lonchidion, Lepisosteus occidentalis, small mammals, amphibians, and reptiles like Didelphodon, Protalphadon, Cimolestes, Meniscoessus, Nanocuris, Palaeobatrachus, Palaeosaniwa, Chamops, Axestemys, Basilemys, sea turtle, Toxochelys, Thoracosaurus, Borealosuchus, Champsosaurus, Brodavis, Scahperpeton, Habrosaurus, Casterolimulus, Myledaphus, and Brachychampsa hatchlings, normally targeted by adolescents and hatchlings.

The young are precocial, with their parents only there to protect them and guide them to food. They learn to hunt by chasing small animals and dinosaurs including sea turtle hatchlings along the coast and ducking their heads underwater to catch fish in wetlands. Adult Tyrannosaurus would occasionally cannibalize younger Tyrannosaurus that weren't related to them and especially after a fight over territory where the loser is badly wounded.

Tyrannosaurs would sometimes eat plants to relieve themselves as a form of digestive ailment.

Feeding Strategies: Tyrannosaurus is the apex predator of Hell Creek. A hyper-carnivore, it will eat most animals as an adult but prefers the slow-moving Anatosaurus and Triceratops as prey, targeting young and weak individuals as most smaller prey are too fast and nimble.

Most paleontologists accept that Tyrannosaurus was both an active predator and a scavenger like most large carnivores. Tyrannosaurus had multiple weapons in its arsenal that it could use: its teeth, its tail, its giant foot claws, and the head which could be used as a devastating battering ram. Their eyes can see in binocular vision like hawks, which means, unlike some movies, if you stand still it won't see which is due to the frog gene you're still going to get eaten. Their teeth were the size and shape of a banana and they could use their great bellow roars to disorient close-by creatures, prey or predator.

They are unusually clever in their hunting strategies which involve rudimentary trap-setting and cooperative tactics. Recent studies suggest that T. rex and related tyrannosaurids may have been far smarter than we used to think, to the point of potentially being some of the most intelligent non-avian dinosaurs of all. When hunting the younger adolescents and sub-adults being slender and agile drive the prey they separate to an ambush site where the bulky adults hide before they attack.

A study in 2012 by Karl Bates and Peter Falkingham found that Tyrannosaurus had the most powerful bite of any terrestrial animal that has ever lived, finding an adult Tyrannosaurus could have exerted 35,000 to 57,000 N (7,868 to 12,814 lbs) of force in the back teeth. This allowed it to crush bones during repetitive biting and fully consume the carcasses of large dinosaurs. Stephan Lautenschlager and colleagues calculated that Tyrannosaurus was capable of a maximum jaw gape of around 80 degrees, a necessary adaptation for a wide range of jaw angles to power the creature's strong bite.

A debate exists, however, about whether Tyrannosaurus was primarily a predator or a pure scavenger. The debate originated in a 1917 study by Lambe which argued that large theropods were pure scavengers because Gorgosaurus teeth showed hardly any wear. This argument disregarded the fact that theropods replaced their teeth quite rapidly. Ever since the first discovery of Tyrannosaurus, most scientists have speculated that it was a predator; like modern large predators, it would readily scavenge or steal another predator's kill if it had the opportunity.

Paleontologist Jack Horner has been a major proponent of the view that Tyrannosaurus was not a predator at all but instead was exclusively a scavenger. He has put forward arguments in the popular literature to support the pure scavenger hypothesis:

-Tyrannosaur arms are short when compared to other known predators. Horner argues that the arms were too short to make the necessary gripping force to hold on to prey. Other paleontologists such as Thomas Holtz Jr. argued that there are plenty of modern-day predators that do not use their forelimbs to hunt such as wolves, hyenas, and secretary birds as well as other extinct animals thought to be predators that would not have used their forelimbs such as phorusrhacids.

-Tyrannosaurs had large olfactory bulbs and olfactory nerves (relative to their brain size). These suggest a highly developed sense of smell that could sniff out carcasses over great distances, as modern vultures do. Research on the olfactory bulbs of dinosaurs has shown that Tyrannosaurus had the most highly developed sense of smell of 21 sampled dinosaurs.

-Tyrannosaur teeth could crush bone and therefore could extract as much food (bone marrow) as possible from carcass remnants, usually the least nutritious parts. Karen Chin and colleagues have found bone fragments in coprolites (fossilized feces) that they attribute to tyrannosaurs, but point out that a tyrannosaur's teeth were not well adapted to systematically chewing bone like hyenas do to extract marrow.

-Since at least some of Tyrannosaurus's potential prey could move quickly, evidence that it walked instead of ran could indicate that it was a scavenger. On the other hand, recent analyses suggest that Tyrannosaurus, while slower than large modern terrestrial predators, may well have been fast enough to prey on large hadrosaurs and ceratopsians.

Other evidence suggests hunting behavior in Tyrannosaurus. The eye sockets of tyrannosaurs are positioned so that the eyes would point forward, giving them binocular vision slightly better than that of modern hawks. It is not obvious why natural selection would have favored this long-term trend if tyrannosaurs had been pure scavengers, which would not have needed the advanced depth perception that stereoscopic vision provides. In modern animals, binocular vision is found mainly in predators.

A 2021 study focused on the vision and hearing of the small theropod Shuvuuia, to which Tyrannosaurus was compared suggests that Tyrannosaurus was diurnal and would have hunted predominantly during daylight hours, a feature it shared with Dromaeosaurus, a third dinosaur compared to Shuvuuia in the study.

A skeleton of the hadrosaurid Edmontosaurus annectens has been described from Montana with healed tyrannosaur-inflicted damage on its tail vertebrae. The fact that the damage seems to have healed suggests that the Edmontosaurus survived a tyrannosaur's attack on a living target, i.e. the tyrannosaur had attempted active predation. Despite the consensus that the tail bites were caused by Tyrannosaurus, there has been some evidence to show that they might have been created by other factors. For example, a 2014 study suggested that the tail injuries might have been due to Edmontosaurus individuals stepping on each other, while another study in 2020 backs up the hypothesis that biomechanical stress is the cause of tail injuries. There is also evidence of an aggressive interaction between a Triceratops and a Tyrannosaurus in the form of partially healed tyrannosaur tooth marks on a Triceratops brow horn and squamosal (a bone of the neck frill); the bitten horn is also broken, with new bone growth after the break. It is not known what the exact nature of the interaction was, though either animal could have been the aggressor. Since the Triceratops' wounds healed, it is most likely that the Triceratops survived the encounter and managed to overcome the Tyrannosaurus. In a battle against a bull Triceratops, the Triceratops would likely defend itself by inflicting fatal wounds on the Tyrannosaurus using its sharp horns. Studies of Sue found a broken and healed fibula and tail vertebrae, scarred facial bones, and a tooth, from another Tyrannosaurus embedded in a neck vertebra, providing evidence for aggressive behavior. Studies on hadrosaur vertebrae from the Hell Creek Formation that were punctured by the teeth of what appears to be a late-stage juvenile Tyrannosaurus indicate that despite lacking the bone-crushing adaptations of the adults, young individuals were still capable of using the same bone-puncturing feeding technique as their adult counterparts.

"A sketch was doodled of Numbuh 4 being in great pain being wedgied by Tyrannor with his underwear hanging from his jaws."

Tyrannosaurus may have had infectious saliva used to kill its prey, as proposed by William Abler in 1992. Abler observed that the serrations (tiny protuberances) on the cutting edges of the teeth are closely spaced, enclosing little chambers. These chambers might have trapped pieces of the carcass with bacteria, giving Tyrannosaurus a deadly, infectious bite much like the Komodo Dragon was thought to have. Jack Horner and Don Lessem, in a 1993 popular book, questioned Abler's hypothesis, arguing that Tyrannosaurus's tooth serrations were more like cubes in shape than the serrations on a Komodo monitor's teeth, which are rounded.

Tyrannosaurus, and most other theropods, probably primarily processed carcasses with lateral shakes of the head, like crocodilians. The head was not as maneuverable as the skulls of allosauroids, due to the flat joints of the neck vertebrae.

Cannibalism: Evidence also strongly suggests that tyrannosaurs were at least occasionally cannibalistic. Tyrannosaurus itself has strong evidence pointing towards it having been cannibalistic in at least a scavenging capacity based on tooth marks on the foot bones, humerus, and metatarsals of one specimen. Fossils from the Fruitland Formation, Kirtland Formation (both Campanian in age), and the Maastrichtian-aged Ojo Alamo Formation suggest that cannibalism was present in various tyrannosaurid genera of the San Juan Basin. The evidence gathered from the specimens suggests opportunistic feeding behavior in tyrannosaurids that cannibalized members of their species. A study from Currie, Horner, Erickson, and Longrich in 2010 has been put forward as evidence of cannibalism in the genus Tyrannosaurus. They studied some Tyrannosaurus specimens with tooth marks in the bones, attributable to the same genus. The tooth marks were identified in the humerus, foot bones, and metatarsals, and this was seen as evidence of opportunistic scavenging, rather than wounds caused by intraspecific combat. In a fight, they proposed it would be difficult to reach down to bite in the feet of a rival, making it more likely that the bitemarks were made in a carcass. As the bitemarks were made in body parts with relatively scanty amounts of flesh, it is suggested that the Tyrannosaurus was feeding on a cadaver in which the more fleshy parts already had been consumed. They were also open to the possibility that other tyrannosaurids practiced cannibalism.

The rescue team observed an attempt of another male T. Rex stealing the kill from the mother T. Rex, who has offspring which resulted in a fight leading to the female being badly wounded just as he was about to kill her, it wasn't until her mate showed up to save her, fought off his rival, and drove him off.

Territorial Fighting: Tyrannosaurs were territorial and often had large-range territories to occupy one or a family pack. Adult Tyrannosaurus will occupy large territories to sustain their requirements for food, defending their territories diligently. When two adults meet outside of the breeding season, the results are usually violent, with face biting being common in these conflicts often these adults are a wanderer or a challenger ready to lay claim to the Tyrannosaurus, or in case the pack would be involved, engage and attack.

How fights play out during a territorial dispute between two fully-grown Tyrannosaurus rex that can escalate into a full-blown fight after neither was willing to back down. The two massive predators charge and bite at each other fiercely, their powerful jaws capable of crushing bone being great weapons in combat as well, and both manage to cause the other injuries, but the victor is clear when one manages to knock the other over onto the ground. The winner has decided to go even further and rip their opponent's jaw clean off, permanently deforming the other tyrannosaur and ruining (if not ending) its life before driving his foe away or killing it. Sometimes whole Tyrannosaur family packs would take over the territory of another pack and kill them and drive the survivors off.

There are various specimens of large tyrannosaurs, including some of Tyrannosaurus rex itself, that show bite marks matching others of their kind, especially on the face, proving that biting (and particularly face biting) were common in their intraspecific combat. These fights can commonly result in losing limbs and parts of their jaws or tails.

Parenting: While there is no direct evidence of Tyrannosaurus raising their young (the rarity of juvenile and nest Tyrannosaur fossils has left researchers guessing), it has been suggested by some that like its closest living relatives, modern archosaurs (birds and crocodiles) Tyrannosaurus may have protected and fed its young. Crocodilians and birds are often suggested by some paleontologists to be modern analogs for dinosaur parenting.

Direct evidence of parental behavior exists in other dinosaurs such as Maiasaura peeblesorum, the first dinosaur to have been discovered to raise its young, as well as more closely related Oviraptorids, the latter suggesting parental behavior in theropods.

Based on our current research studies, The Parents and older offspring take care of and look after their offspring from other predators and guide them to food and show them how to hunt. The older offspring would stick around with their parents and raise their younger siblings as a way to learn how to care for their offspring once they leave to start their packs.

Tyrannosaurus parents would make a nest mound that acts like an incubator out of debris, damp soil, leaves, sticks, and their droppings after the female lays about eight to fifteen eggs before burying them. The parents would take turns guarding the eggs against egg-stealing predators and once they hear their warbles and cries meaning the eggs had hatched, they use their jaws to break through the nest and sometimes hit their jaws to help crack open the eggs.

Parents would carry their newly hatched young in their jaws when relocating to a different location and even use their arms to carry them. To call their young the parents would make deep, low-pitched cries, barely audible to humans, to which the chicks respond with chirps, warbles, and a high-pitched cry almost similar to a frog croak when threatened or far away.

Tyrannosaurus displays strong parental care by watching over broods for years until their young reaches a moderate size. When this occurs, the parents depart or drive them away seeing them more as food, but the juveniles stay together in a sibling pack, hunting prey together until they reach adulthood. Unlike the adults, the younger Tyrannosaurus is extraordinarily fast. Young Tyrannosaurus use this trait to their advantage in hunting prey such as the Ornithomimus and Anzu.

Lone Juveniles without siblings would join a loosely knitted coalition pack led by an elder Tyrannosaur, although it can be risky as the juvenile would be rejected and chased away sometimes to the death as well.

Pathology: In 2001, Bruce Rothschild and others published a study examining evidence for stress fractures and tendon avulsions in theropod dinosaurs and the implications for their behavior. Since stress fractures are caused by repeated trauma rather than singular events they are more likely to be caused by regular behavior than other types of injuries. Of the 81 Tyrannosaurus foot bones examined in the study, one was found to have a stress fracture, while none of the 10 hand bones were found to have stress fractures. The researchers found tendon avulsions only among Tyrannosaurus and Allosaurus. An avulsion injury left a divot on the humerus of Sue the T. rex, apparently located at the origin of the deltoid or teres major muscles. The presence of avulsion injuries being limited to the forelimb and shoulder in both Tyrannosaurus and Allosaurus suggests that theropods may have had musculature more complex than and functionally different from those of birds. The researchers concluded that Sue's tendon avulsion was probably obtained from struggling prey. The presence of stress fractures and tendon avulsions, in general, provides evidence for a "very active" predation-based diet rather than obligate scavenging.

A 2009 study showed that smooth-edged holes in the skulls of several specimens might have been caused by Trichomonas-like parasites that commonly infect birds. According to the study, seriously infected individuals, including "Sue" and MOR 980 ("Peck's Rex"), might therefore have died from starvation after feeding became increasingly difficult. Previously, these holes had been explained by the bacterial bone infection Actinomycosis or by intraspecific attacks. A subsequent study found that while trichomoniasis has many attributes of the model proposed (osteolytic, intra-oral) several features assume that it was the cause of death less supportable by evidence. For example, the observed sharp margins with little reactive bone shown by the radiographs of Trichomonas-infected birds are dissimilar to the reactive bone seen in the affected T. rex specimens. Also, trichomoniasis can be very rapidly fatal in birds (14 days or less) albeit in its milder form, and this suggests that if a Trichomonas-like protozoan is the culprit, trichomoniasis was less acute in its non-avian dinosaur form during the Late Cretaceous. Finally, the relative size of this type of lesion is much larger in small bird throats, and may not have been enough to choke a T. rex. A more recent study examining the pathologies concluded that the osseous alteration observed most closely resembles those around healing human cranial trepanations and healing fractures in the Triassic reptile Stagonolepis, in the absence of infection. The possible cause may instead have been intraspecific combat.

One study of Tyrannosaurus specimens with tooth marks in the bones attributable to the same genus was presented as evidence of cannibalism. Tooth marks in the humerus, foot bones, and metatarsals, may indicate opportunistic scavenging, rather than wounds caused by combat with another T. rex. Other tyrannosaurids may also have practiced cannibalism.

Based on the observations of the Adults, they were covered with scars mostly during fights with heavily armored prey and other Tyrannosaurs, most prominent in the Males mostly in the face. There are also other pathology characteristics like blindness in one eye, the tip of the tail gone, and tumors from an avian disease.

Tyrannosaurs would wallow in long-flowing river water to help clean their wounds and even in mud which contains high concentrations of minerals such as magnesium and can hold heat for a long period. It helps heal wounds, reduce skin inflammation, treat joint pain, stimulate blood circulation, enhance lymphatic flow, and cleanse the skin.

Communication: Most Depictions show T. Rex roaring like how mammals roar like Lions and bears which is false. Later Research and Observations have shown they make rumbles and bellows similar to crocodilians like alligators and birds like bitterns and cassowaries and they mostly communicate by closed-mouth bellowing which can be heard from miles.

The tyrannosaurs initially assume low postures and open mouths bellowing, growling, and hissing in aggressive confrontation.

Adults make deep, low-pitched cries to their Chicks which they respond with a high-pitched cry almost similar to a frog croak when threatened or far away.

During the breeding season, males and females locate each other and emit low-frequency sounds during courtship.

Reproduction: T. Rex courtship is dangerous, females are tougher, often taller, and more aggressive than the male and could kill him. So males develop ways to court their mates, first is a test of strength like a Tyrannosaurus rex felling a tree with the help of his thick, muscular tail pushing the tree to a location where a potential mate can easily find it. The uprooted tree serves as a potential hunting blind and a "bait" for passing herbivores, making it an impressive gift for any female Tyrannosaurus. Males of many species engage in seemingly pointless acts designed to show off their strength - to potential rivals as well as the members of the opposite sex. Males rely on such exercises of power to establish their social dominance and mark themselves as suitable mating partners.

First, the male waits in his blind for a passing herbivore like Triceratops or Edmontosaurus as a courting gift although they can be dangerous, the larger the kill the chances are the female would stay and prove to the female that he can be a good hunter and partner for her.

Second, is a test of strength like a Tyrannosaurus rex felling a tree with the help of his thick, muscular tail pushing the tree to a location where a potential mate can easily find it. The uprooted tree serves as a potential hunting blind and a "bait" for passing herbivores, making it an impressive gift for any female Tyrannosaurus. The Male also makes a bower display which can consist of dinosaur bones, flowers, tree branches, and colorful rocks which can be a playground for the youngsters.

Third, the male makes close mouth rumbling bellows in low-frequency that can reach for several miles and the female would respond and follow the source of the sound to the male.

Finally, the male gives the female space as she feeds, and around the time she is finished, The male tilts his head and his posture standing high up with his tail for support bellows with his throat showing her his bright red throat sac to prove his status and health. If the female accepts she joins in the ritual and they nuzzle each other's snouts. After mating, they will form a mated pair bond as they will both guard their territory and raise the young together.

Paleoecology: Tyrannosaurus lived during what is referred to as the Lancian faunal stage (Maastrichtian age) at the end of the Late Cretaceous. Tyrannosaurus ranged from Canada in the north to at least New Mexico in the south of Laramidia. During this time Triceratops was the major herbivore in the northern portion of its range, while the titanosaurian sauropod Alamosaurus "dominated" its southern range. Tyrannosaurus remains have been discovered in different ecosystems, including inland and coastal subtropical, and semi-arid plains.

Several notable Tyrannosaurus remains have been found in the Hell Creek Formation. During the Maastrichtian, this area was subtropical, with a warm and humid climate. The flora consisted mostly of angiosperms but included trees like dawn redwood (Metasequoia) and Araucaria. Tyrannosaurus shared this ecosystem with ceratopsians including Leptoceratops, Torosaurus, and Triceratops, the hadrosaurid, Edmontosaurus annectens, the parksosaurid, Thescelosaurus, the ankylosaurs, Ankylosaurus and Denversaurus, the pachycephalosaurs, Pachycephalosaurus and Sphaerotholus, and the theropods like Ornithomimus, Struthiomimus, Acheroraptor, Dakotaraptor, Pectinodon, and Anzu.

Another formation with Tyrannosaurus remains is the Lance Formation of Wyoming. This has been interpreted as a bayou environment similar to today's Gulf Coast. The fauna was very similar to Hell Creek, but with Struthiomimus replacing its relative Ornithomimus. The small ceratopsian Leptoceratops also lived in the area.

In its southern range, Tyrannosaurus lived alongside the titanosaur Alamosaurus, the ceratopsians Torosaurus, Bravoceratops, and Ojoceratops, hadrosaurs which consisted of a species of Edmontosaurus, Kritosaurus, and a possible species of Gryposaurus, the nodosaur, Glyptodontopelta, the oviraptorid, Ojoraptosaurus, possible species of the theropods Troodon and Richardoestesia, and the pterosaur, Quetzalcoatlus. The region is thought to have been dominated by semi-arid inland plains, following the probable retreat of the Western Interior Seaway as global sea levels fell.

Tyrannosaurus may have also inhabited Mexico's Lomas Coloradas formation in Sonora. Though skeletal evidence is lacking, six shed and broken teeth from the fossil bed have been thoroughly compared with other theropod genera and appear to be identical to those of Tyrannosaurus. If true, the evidence indicates the range of Tyrannosaurus was possibly more extensive than previously believed. It is possible that tyrannosaurs were originally Asian species, migrating to North America before the end of the Cretaceous period.

Population Estimates: According to studies published in 2021 by Charles Marshall et al., the total population of adult Tyrannosaurus at any given time was perhaps 20,000 individuals, with computer estimations also suggesting a total population no lower than 1,300 and no higher than 328,000. The authors themselves suggest that the estimate of 20,000 individuals is probably lower than what should be expected, especially when factoring in that disease pandemics could easily wipe out such a small population. Throughout the genus' existence, it is estimated that there were about 127,000 generations and that this added up to a total of roughly 2.5 billion animals until their extinction.

In the same paper, it is suggested that in a population of Tyrannosaurus, adults numbering 20,000, the number of individuals living in an area the size of California could be as high as 3,800 animals, while an area the size of Washington D.C. could support a population of only two adult Tyrannosaurus. The study does not take into account the number of juvenile animals in the genus present in this population estimate due to their occupation of a different niche than the adults, and thus it is likely the total population was much higher when accounting for this factor. Simultaneously, studies of living carnivores suggest that some predator populations are higher in density than others of similar weight (such as jaguars and hyenas, which are similar in weight but have vastly differing population densities). Lastly, the study suggests that in most cases, only one in 80 million Tyrannosaurus would become fossilized, while the chances were likely as high as one in every 16,000 of an individual becoming fossilized in areas that had more dense populations.

Meiri (2022) questioned the reliability of the estimates, citing uncertainty in metabolic rate, body size, sex and age-specific survival rates, habitat requirements, and range size variability as shortcomings Marshall et al. did not take into account. The authors of the original publication replied that while they agree that their reported uncertainties were probably too small, their framework is flexible enough to accommodate uncertainty in physiology and that their calculations do not depend on short-term changes in population density and geographic range, but rather on their long-term averages. Finally, they remark that they did estimate the range of reasonable survivorship curves and that they did include uncertainty in the time of onset of sexual maturity and the growth curve by incorporating the uncertainty in the maximum body mass.

Interactions with other species: Herbivores like Triceratops, Torosaurus, Ankylosaurus, Edmontosaurus, Pachycephalosaurus, Ornithomimus, Thescelosaurus, and Denversaurus were prey to T. Rex had to evolve defenses whether be horns, frills, osteoderm armor, club tails, dome heads, long tails, and living in herds to protect themselves from T. Rex.

Triceratops and Torosaurus dislike T. Rex and would fight using their frills and horns for defense as they often go for the sides and bellies, and herds form a circle around the young with their frills and horns as shield walls against the large predators and would mock charge together as a herd. Triceratops or Torosaurus is often targeted from the back of the frill where the neck and throat are, but occasionally the legs and spines too. An adult T. Rex can take down a Triceratops or Torosaurus single-handed, but not without its risks leading to injuries or death on either side. A cooperative-coordinated pack of T. Rex can easily take both of them down by separating the weakest from the herd and attacking from all sides.

Ankylosaurus and Denversaurus mostly stand their ground against T. Rex due to their armor, osteoderm-covered bodies, and club tails which can injure their legs. The babies are vulnerable and the only vulnerable spot is the belly. A large desperate pack could take down an Ankylosaurus by working together.

Alamosaurus adults have no predators, although weak and young are targeted by T. Rex normally in large groups. Alamosaurus can fight back using their bulky body to push down, rearing up to make themselves bigger and threatening, their long legs to pin down and kick, and long necks and tails to whip and hit their opponents.

Ornithomimus, Anzu, and Thesecelosaurus rely on their speed when being chased; they are normally targeted by adolescents although weak and lagging targets are acceptable for adults based on our observations with the Female hunting an Ornithomimus. If cornered the Ornithomimus and Thescelosaurus will fight back with their arm claws, peaks from their beaks, and kicking with their legs.

Leptoceratops targeted by both Adults and Adolescents would retreat to their burrows to hide and fight back with their sharp beaks with their heads blocking the entrance.

Pachycephalosaurus is difficult prey, for both adults and adolescents as the Pachycephalosaurus would charge and ram the T. Rex with their dome-shaped heads on the sides.

Other predators are often seen as a threat or annoyance as they would scavenge their kills before being driven off, same with the Pectinodons. They normally don't eat other predators due to diseases and ignore them. Some Tyrannosaurs may ignore Dakotaraptors as they let them feed on their kills when they're finished and Dakotaraptors would follow Tyrannosaurs and alert them of other threats. But there are rare cases of large Dakotaraptor aggregations that would swarm and kill an injured or badly wounded T. Rex.

For adolescents, Juveniles, chicks, and eggs are often seen as prey to Predators like Dakotaraptors if their parents or older siblings aren't around, Acheroraptors, Pectinodons, and Dromaeosaurus even small mammals and reptiles like Didelphodon, Nanocuris, Alphadon, Cimolestes, Palaeosaniwa, Dinilysia, would feed on T. Rex chicks and eggs if given the chance.

One Interesting Observation made by the Rescue Team when they observe that Trierarchuncus, a species of Alvarezsaurs, often hangs out near Tyrannosaurs they provide a service by cleaning the T. Rex's teeth by feasting on bits of meat scraps stuck between the teeth for protein supplements like how some birds and fish are cleaning teeth of carnivores like sharks and crocodiles and it seems Avisaurus would do the same behavior pecking insects and parasites off the T. Rex and even licking blood off their wounds.

Another detail of Trierarchuncus is that Tyrannosaurs often ignore them, these alvarezsaurs would follow tyrannosaurs to their kills feeding on small scraps of meat and bugs attracted to the tyrannosaurs and the kill feeding on dermestid beetles and flies both adults and maggots. They would even rest on top of the nest and alert the T. Rex parents of egg thieves and the chicks often love to chase them about as a form of play.

Trierarchunus isn't the only symbiosis partner, like jackals and tigers, Some Acheroraptors would follow adult T. Rexes to their kills after the large theropods finish eating and they will alert Tyrannosaurs to dead kills and protect them from other predators. Acheroraptors would act as nest protectors from other Tyrannosaurs, babysitters to the T. Rex young that even the Acheroraptor young become playmates with the T. Rex young, and even lay their eggs in the T. Rex Nest. Some scientists have theorized that individual Acheroraptors may even develop special bonds with individual T. Rex.

When they wade in the waterways, both adult and young would sometimes catch aquatic life like fish, although some are powerful and have teeth to fight back including Paleopsephurus, Lonchidion, Lepisosteus, Casterolimulus, Myledaphus, Axestemys, Scapherpeton, Melvius, and Habrosaurus. Axestemys, Scapherpeton, Melvius, and Habrosaurus will nip and fight back while Melvius would prey on the hatchlings.

In Coastal areas, when a Tyrannosaurus swims to the neighboring islands they are vulnerable to Mosasaurus, an Adult can fight one off if close to the shallows, but the youngsters are at their most vulnerable. Mosasaurus would even scavenge on beached carcasses and would compete with theropods during high tide.

Juvenile and Adolescent T. Rex would prey on Chamops, Alphadon, Cimolestes, Meniscoessus, Palaeosaniwa, Dinilysia, Didelphodon, Basilemys, Brodavis, Palaeobatrachus, although some of them will fight back.

Crocodilians and Choristoderes, Thoracosaurus, Borealosuchus, Champsosaurus, and Brachychampsa, prey on young and juveniles wading and drinking in the water, but young and juvenile T. Rex prey on hatchlings and juveniles of the Crocodilians and Choristoderes. Adult Crocodilians and Choristoderes are targeted by Adult T. Rex if the theropods manage to catch and kill them.

Quetzalcoatlus is a predator to young T. Rexes and a foe over carcasses. Both species of pterosaurs would fly about and mob Tyrannosaurs pecking at them, but if given the chance the T. rex would turn the tables and kill the large pterosaur if it doesn't take off on time.

Extinction: Despite popular belief, it wasn't the singular large asteroid that killed Tyrannosaurus Rex and the rest of the dinosaur dynasty. The large asteroid carried a gravitational field of its own and picked smaller asteroids, comets, and meteors in it while it headed in the direction of Earth. With the sun blocked off causing plants to die off leading to the dying off of herbivores, it would be a feast for predators like T. Rex, but eventually, they will starve themselves into extinction.

Cultural significance: Since it was first described in 1905, T. rex has become the most widely recognized dinosaur species in popular culture. It is the only dinosaur that is commonly known to the general public by its full scientific name (binomial name) and the scientific abbreviation T. rex has also come into wide usage. Robert T. Bakker notes this in The Dinosaur Heresies and explains that "a name like 'T. rex' is just irresistible to the tongue.

"There is a size comparison made by Tracey Sketchitt of Tyrannosaurus with two T. Rex Pokémon, Tyrunt and Tyrantrum, and Clemont, Bonnie, and Dedenne forming the human base size comparison."

"A T. rex will always draw attention, but I shouldn't have to remind you how dangerous they can be. The world has never seen a more alpha predator." -Kim Possible.

Danger Tip: Tyrannosaurus is an aggressive species. The good news: they won't attack for no reason. Bad news: they don't need much of a reason. All you have to do is get into their personal space or look them directly in the eye and you can find yourself on the wrong side of a Tyrannosaur's mouth.

Significant Events: A Pack of Four T. Rexes was rescued during the Park's First mission and among the last to be rescued. The Rescue Team encountered a trio of subadults after they tried to capture an Ornithomimus from the flock, but managed to escape them.

On the second day, Courage found footprints leading the team to a valley littered with bones, the center territory for a pack of T. Rex including a sleeping breeding pair, and roughhousing subadults; they stay hidden as the pack departs.

The Next Day, the same pack attacks the mixed-species herd of herbivores gathering around a creek after most of the dinosaurs run off. They turned their attention to a lone Alamosaurus and were very desperate to take this one down. They would later be scared off by the portal when the Team decides to rescue the Sauropod.

The Team also observed an Adult Female joining a hunt only to be injured by the thigh of a mother Triceratops when she grabbed a baby in her jaws. The Team decided to track her during that time, Charlie's Group had a dangerous encounter with a large male who gave Numbuh 4 wedgies as it shook the Aussie boy around. It later tried to attack Charlie who hid in a log alongside a Dromaeosaurus and a Dinilysia snake, but managed to escape. The Female was the one observed with the Trierarchuncus cleaning its teeth and was later found near a river washing its wounds in the water. It has found a washed-up dead Triceratops but was unable to reach it and was taken over by a flock of Quetzalcoatlus.

On the day of the Asteroid, The Female was seen again chasing a Mixed-Species herd of Herbivore Dinosaurs managing to snatch a weak Ornithomimus lagging. The Rescue Team found out the female they followed was a mother of two adolescents in a cave, but a rival male, a threat to her and her babies, challenged her leaving the female very badly wounded. It wasn't until the arrival of the same male showed up to fight off and drive the rival away, that it turns out this was the female's mate and father of adolescents. They would later be rescued when the Meteorite struck the earth and just in time before they were hit by the wave of ash clouds and debris. They now reside in the T. Rex Kingdom of the Hell Creek Section of Prehistoric Park.

T. Rex Kingdom: A large paddock mostly covered with forests with few open clearings and waterways to replicate the Hell Creek Floodplain environment. They have a large hill they can walk up to the top to overlook their domain, and establish dominance roars. A river flows through the paddock into one of the moats which is one of the visitor viewing areas. They are normally fed with pre-killed cows left out in the clearing, fed by a feeding crane, or meat placed in an artificial Triceratops model. It mostly has elevated moats in the surrounding areas, steel bar fencing in the holding areas, and a viewing area which is wooden pole fencing with the moat hidden by plants on the top edge. There is a large steel bar fencing in an elevated deep moat ravine that separates the T. Rex from the other herbivores in the Hell Creek Multi-Species Paddock which is hidden to give the illusion these dinosaurs are in the same space.

Notable Individuals:

Tyrannor: An Adult Male named after the character from Dink, the Little Dinosaur. He is a caring father and mate to Rexy and their offspring.

Rexy: An Adult Female named after the Iconic T. Rex from Jurassic Park and Night at the Museum. She is a caring mother and mate to Tyrannor and their offspring. She is taller than Tyrannor.

Matilda: A young female and older sister of Terrence.

Terrence: A young male and younger brother of Matilda. He formed a bond with Thomas Tran.

Conclusion: Prehistoric Park's pack may be dangerous, but is truly a sight to behold. When they bellow roar, it sounds like the very earth is roaring, and they are extremely protective parents. As long as they are in a visitor-safe and proper environment, they will be available for the world to wonder at for generations.

Note:

Since there is a lot of information to talk about Tyrannosaurus Rex, you can check out the other chapters detailing Tyrannosaurus specimens, feeding behavior, and role in Popular Culture.

The Field Guide might take a long time, like structuring and writing descriptions of the creatures, but also my time in college and spending time with my family. So you can suggest additional information quotes, descriptions, and natural or speculative behaviors for the prehistoric animals that I can edit and you send your suggestions either in reviews or Private Messages.

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