Palaeosaniwa canadensis
Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Anguimorpha
Genus: Palaeosaniwa
Type Species: Palaeosaniwa canadensis meaning "Ancient Saniwa from Canada."
Described by Charles W. Gilmore, 1928
Common Name: Hell Creek Monitor Lizard
Synonym:
-Megasaurus robustus, Gilmore, 1928.
Current Park Population: (5; 2 male, 3 female)
Park Diet: Pre-killed rats, pigs, chicken, deer, and meat slices.
Natural Diet: Small Mammals, Fish, Amphibians, Birds, small Non-Avian Dinosaurs, and the eggs and juveniles of Large Dinosaurs.
Lifespan: 30 Years.
Habitat: Open-Canopy Forests, Floodplain Swamps, and Fern Prairies.
Native Ecosystem: Western North America, on what was then an island continent known as Laramidia. Hell Creek Formation, and Dinosaur Park Formation, Southwestern Alberta, Canada, Montana and Wyoming, USA, Late Cretaceous-Early Eocene, 70.6-66 Million Years Ago, Late Campanian-Maastrichtian Stages.
Breeding Season: Late April to early June.
Gestation Period: Nine-Ten Months.
Eggs Laid: 12 Eggs.
Hatching Time: April-June
Danger Level: 8 out of 10.
Park Star Rating: 2 Star
Summary: There were large lizards in Hell Creek like the Palaeosaniwa, Although it can grow as large as a Komodo dragon, Palaeosaniwa is an early relative of the modern Gila Monster (Monstersauria). Like its modern relatives, Palaeosaniwa is venomous, but this feature is used for defense more than prey capture, latching onto threats with its hooked teeth while glands on the lower jaw excrete venom into the wound. This animal acts primarily as a specialized raider of dinosaur nests, making Palaeosaniwa a primary enemy of hatchling-stage dinosaurs and protective parents."
Description: Palaeosaniwa was roughly comparable to a large monitor lizard (Varanidae) in size. Individuals are colored similarly to Gila monsters covered with light brown scales, black and white stripes, visible around the tail, and blackheads with the males having orange dewlap throats, black feet, and white spots.
Size: Measuring around 3–3.5 m (9.8–11.5 ft) in length, it is among the largest terrestrial lizards known from the Mesozoic era (though Asprosaurus may compete with it in size. A later study shows an estimation with snout–vent length of about 85 centimeters (33 in) for Maastrichtian species.
Classification: Palaeosaniwa is a member of the Platynota, a group that includes the monitor lizards (Varanidae) and Gila monsters (Helodermatidae). Originally, it was thought to be a member of the Varanidae, but has also been interpreted as a relative of the Helodermatidae. The most recent analysis places Palaeosaniwa outside of either Varanidae or Helodermatidae, as a stem member of the Varanoidea. Its precise affinities remain poorly understood, but it may be related to other Late Cretaceous, North American carnivorous lizards such as Parasaniwa, Paraderma, Labrodioctes, and Cemeterius.
Dentition and Diet: It is similar to modern varanid lizards (particularly the Komodo dragon) in having bladelike teeth with minute serrations. These teeth would have been effective for seizing and cutting large prey items, and suggest that Palaeosaniwa fed on other vertebrates. Adult Palaeosaniwa would have been large enough to prey on any of the avialans or mammals known from the time, small non-avian dinosaurs, and the eggs and juveniles of large dinosaurs.
Distribution: Palaeosaniwa was originally described from the late Campanian of Alberta. More recently it has been reported from the late Campanian of Montana, and the late Maastrichtian of Montana and Wyoming. It is known primarily from isolated teeth and vertebrae, but two partial skeletons have also been discovered. The type species, P. canadensis, is from Alberta. Although the Maastrichtian Palaeosaniwa has traditionally been referred to as this species, it succeeds it by roughly ten million years. Given the distance in time between these animals, they are likely to represent distinct species, but the available fossils are too incomplete to be certain.
Interactions with other species: Large and Small Dinosaurs are quite defensive with these lizards as they would prey on them, their babies, and their young including Thescelosaurus, Ornithomimus, Torosaurus, Ankylosaurus, Alamosaurus, Trierarchuncus, Leptoceratops, Triceratops, Anzu, Denversaurus, Tyrannosaurus, Acheroraptor, Dakotaraptor, Dromaeosaurus, Pectinodon, pterosaurs like Quetzalcoatlus, and crocodile-like animals Brachychampsa,
They prey on small animals both adults and young of Basilemys, Axestemys, Palaeobatrachus, Scapherpeton, Habrosaurus, Casterolimulus, Alphadon, Dinilysia, Cimolestes, Didelphodon, Brodavis, Meniscoessus, and scavenge dead fish washed up on the water's edge.
They are on the menu for most predators and omnivores, both adults and young on land and water like Tyrannosaurus, Acheroraptor, Dakotaraptor, Dromaeosaurus, Pectinodon, Quetzalcoatlus, Ornithomimus, Anzu, Leptoceratops, Triceratops, Torosaurus, Thescelosaurus, Palaeosaniwa, Alphadon, Cimolestes, Lepisosteus occidentalis, Melvius, Didelphodon, Dinilysia, Thoracosaurus, Borealosuchus, Champsosaurus, Axestemys, Brachychampsa, Brodavis, and Lonchidion. But these lizards have a venomous bite that they use to hunt and defend themselves, Although the bite is rarely life-threatening for large animals, but for small animals die quickly.
Extinction: Unfortunately, these lizards despite their generlsit opportunistic diet, the Pslaeosaniwa weren't able to survive the Cretaceous Mass Extinction Event. Their relatives including the modern-day Gila Monsters live on in the Modern Times.
Danger Tip: They are dangerous when handled. Wrangling at least two will be interesting as their venomous bite will require anti-venom to be brought along, or at least vials to milk venom from them and develop anti-venom in response for future keepers in case they get bit. Although the bite is rarely life-threatening, symptoms from a bite may include swelling, intense burning pain, vomiting, dizziness, weakness, rapid heart rate, and/or low blood pressure. Preventing a bite is usually possible.
Significant Events: On the final day, the team encounters a group of Palaeosaniwa basking in the sun as they lounged upon a large rock, alongside Chamops scampering around in search of food like insects and plants three mammals, Cimolestes, Alphadon, and Meniscoessus, scattered throughout the clearing as they fought with each other for food, and a Slither of Dinilysia coiled up on top of a large log basking in the sun. They were scooped up in bags and taken to Prehistoric Park. They now live in the Hell Creek Building.
Hell Creek Building: The Palaeosaniwa live in a pen with ample room to move, a pond to drink from, and a heat lamp to bathe under.
Notable Individual:
Drake: A Male Palaeosaniwa he has formed a bond with Dexter
Conclusion: For Reptile Lovers, Palaeosaniwa is the type of lizard to see on your next visit. They are an example of how lizards occupy niches of modern-day relatives in Prehistoric Times and they would make a deadly venomous addition here at 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.
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