The 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 have knowledge of 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.

44. Paleopsephurus

Paleopsephurus

Scientific Classification

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Class: Actinopterygii

Order: Acipenseriformes

Family: Polyodontidae

Subfamily: Palaeopsephurinae

Genus: Palaeopsephurus

Type Species: Palaeopsephurus wilsoni meaning "Wilson's Before Psephurus."

Described by Archie Justus MacAlpin, 1947.

Common Name: Hell Creek Paddlefish

Current Park Population: (10; all adults; 4 male, 6 female).

Park Diet: Frozen fish like Silversides, gobies, carp, anchovies, shrimp, and crabs.

Natural Diet: small fishes and crustaceans.

Lifespan: 38 years

Habitat: Rivers, Streams, Waterways, Lakes, Creeks, Floodplains, Swamps, lagoons, Estuaries, and Coastal Shores.

Native Ecosystem: Western North America, on what was then an island continent known as Laramidia. Hell Creek Formation, Montana, USA, North America, 93.9-66 Million Years Ago, Turonian-Maastrichtian Stage, Late Cretaceous.

Breeding Season: Mid-March to early April

Eggs Laid: 100,000 eggs

Hatching Time: One to Two Weeks.

Danger Level: 3 out of 10.

Park Star Rating: 1 Star.

Summary: Hell Creek has some bizarre fish one of them is the enigmatic paddlefish, Paleopsephurus known from the Turonian to the Maastrichtian stage (93.9 - 66.0 million years). It is one of two known extinct genera of paddlefish known from the North American fossil record, along with the Eocene Crossopholis. Currently, paddlefish are endangered species, with only one, possibly two extant species known.

History and Classification: The genus was described from three partial specimens currently residing in the collections of the University of Michigan Museum of Paleontology in Ann Arbor, Michigan, USA. Specimen number 22206 U.M. is a complete and well-preserved skull with some denticles, pectoral girdle, and pectoral fins. The second and third specimens were found in a block of matrix from the same location as 2226 U.M. Specimen 22207 U.M. is a portion of the caudal region of a paddlefish, while 22208 U.M. is a partial shoulder with associated pectoral fin. While the specimens were found close to each other, it is impossible to determine if they represent a single individual, and as such were described as three separate fish specimens. The specimens were collected from a sandstone outcrop of the Hell Creek Formation 24 miles (39 km) southeast of Fort Peck, Montana by a University of Michigan Museum of Paleontology expedition in 1938. the fossils were in close association with the holotype specimen of the extinct sturgeon Protoscaphirhynchus squamosus.

The Palaeopsephurus specimens were first studied by American paleontologist and ichthyologist Archie Justus MacAlpin. He published his detailed 1947-type description in the journal Contributions from the Museum of Paleontology, University of Michigan.

There is a sketch of Lisa and Dr. Alvarez going over a specimen of Paleopsephurus at the Royal Woods Natural History Museum. There is also a comparison chart of the Paleopsephurus with the modern-day American Paddlefish and the Now-Extinct Chinese Paddlefish.

Description: The skull is about 274 millimeters (10.8 in) long, suggesting a total body length of about 56 centimeters (22 in). The skull roof is poorly preserved. The stellate bones are loosely packed and more poorly developed compared to the ones in Crossopholis or Polyodon but are similar to those of Psephurus. Its eyes were small and round. The tail fin was heterocercal (spine extending into the upper lobe), with the lower lobe being well developed. The skull is more elongate and narrower than that of the American paddlefish, and lacks the sculpturing present on the skull bones of other paddlefish, with the stellate (star-shaped) bones on the rostrum less numerous than those of the American paddlefish. The teeth were small, sharp, canine shaped, and inward curling, and became proportionally smaller relative to the jaw during growth, and in mature adults were completely fused into the bone. Similar to Polyodon, the jaws were shorter and had a proportionately narrower gape, and unlike the American paddlefish, but similar to fossil paddlefish, the upper jaw was not firmly attached to the braincase. Like other paddlefish, the skeleton was largely cartilaginous. The body lacked scales, except for small scales in the caudal peduncle and caudal fin.

Size: Juveniles attained a weight of around 1 to 1.5 kilograms (2 to 3 pounds) by their first winter and a length of 1 m (3 ft) and a weight of about 3.3 kg (7 lb 4 oz) by the time they were a year old. Beyond this length, proportional weight gain relative to body length dramatically increased, reaching a weight of about 12.5 kg (28 lb) by the time they were around 1.5 m (5 ft) long. They reached sexual maturity at a weight of around 25 kg (55 lb). Adults reached lengths of 0.8 - 0.9 m (2.6-3 ft). Female fish are suggested to have grown larger than male fish once sexually mature, though they grew at similar rates before this.

Individuals are Dark gray with black fins and spots around the white underbelly throat.

Paleobiology

Ecology and Diet: Like other non-Polyodon paddlefish, Paleopsephurus was likely piscivorous. Like modern paddlefishes, it used its large paddle-like rostrum, full of electroreceptors, to detect the diminutive electrical fields created by its prey. In this way, the Paleopsephurus can detect prey in muddy waters, and when it finds one it will proceed in engulfing it with its jaws.

Phylogeny: Paleopsephurus exhibits a combination of characters which suggests that it is more derived than Protopsephurus, but is more basal than Crossopholis, Polyodon, or Psephurus. Relationships of the genera, after Grande et al. (2002).

Life History: Native to the estuaries and coasts of the Hell Creek, the Paddlefish primarily inhabited the large rivers, but sometimes traveled into large lakes. Due to their anadromous nature, mature individuals are found in coastal waters; occasionally spring tides would bring individuals into the lower reaches. The fish was largely solitary and occupied the lower-mid layers of the water column and they are strong swimmers.

Reproduction: The species spent part of its life in the lower section of rivers, including the brackish water of its estuary, but migrated upriver and into major tributaries to congregate for spawning, which occurred in spring, from mid-March to early April. They are normally at least 8 years old. Females likely sexually matured later than males, and probably did not spawn every year, likely every other year or somewhat less frequently, like other acipenseriforms. The ovaries of the female fish contained over 100,000 eggs, each approximately 2.7 mm (3⁄32 in) across. The developing zygotes and fry are restricted to the region upstream, while yearlings and adults were widely distributed throughout the River and waterway proper from the lower to upper reaches.

Interactions with other species: Often ignored by the large dinosaurs, adults and young are prey to predators like Pectinodon, Dromaeosaurus, Acheroraptor, Anzu, Quetzalcoatlus, and juvenile T. Rex, predatory fish like Melvius, sharks, Didelphodon, Borealosuchus, Thoracosaurus, Champsosaurus, Brachychampsa, Axestemys, Palaeobatrachus, Scapherpeton, and Habrosaurus.

Extinction: Due to Freshwater acidification and changing water temperatures would lead to the demise of the Paleopsephrus. But two relatives survive in the 21st century, although the Chinese Paddlefish has been declared extinct due to human activities there are plans to rescue them eventually and the American Paddlefish are still alive today.

Danger Tip: It requires a stretcher to lift one by with a team of people, they can thrash about and could hit you with their rostrum and tails.

Significant Events: On the Team's Final Day of their First Rescue Mission, the team comes upon the Paleopsephurus feeding on small fish alongside Myledaphus swimming and hiding under the river sediment, and a group of Casterolimulus crawling along the river alongside amphibians, Habrosaurus and Scapherpetons, and various fish. They were captured in nets to be transported to the Park. They now reside in the Hell Creek Forest Building.

Hell Creek Forest Building Aquarium: This large tank houses most of the Hell Creek Fishes and aquatic life like Casterolimulus andMyledaphus replicating the freshwater waterways, visitors can view them with underwater thick glass panel viewing. The Paleopsephurus are seen in the lower-mid layers of the water column of the tank.

Conclusion: For Marine life and Aquarium enthusiasts who love bizarre fish will be in awe with our Paleopsephurus as they represent how diverse fish were in Prehistory. Be sure sure to see them on your next visit to Prehistoric Park.

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.

Examples: Inferring what the toons are doodling on the sketches or snarking quotes.

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