#stokesosaurus

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aur naur the hello sore is Earting da snu!!!!

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Dinovember, day 12! A pair of stokesosaurus bickering over a parviraptor 🐍 Tiny snek drumsticks, tastes like chicken?

EDIT, 1/11/22: This entire Dinovember series has been compiled and is now available for purchase on Gumroad! The pages can be printed, or thrown into a digital program! Check it out HERE!

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Dinosaur Profile: Stokesosaurus

An early relative of the great Tyrannosaurus rex, Stokesosaurus provides a window into the early history of the infamous Tyrannosaur family and a new perspective of the giants to be.

Background

Stokesosaurus was described in 1974 by geologist James Henry Madsen amid various Allosaur specimens collected at the famous Cleveland-Dinosaur Quarry in Emery County, Utah as part of the equally famous Morrison Formation. The Morrison Formation dates back to the late Jurassic Period from 156-146 million years ago. It was in these rocks that famous dinosaurs such as the aformentioned Allosaurus, Stegosaurus, Apatosaurus, Brontosaurus, and Brachiosaurus were discovered all the way back to the infamous Bone Wars.

North America during the Late Jurassic almost resembled that of today, having broken apart from Africa and South America during the breakup of the supercontinent Pangea. Instead, it was part of a supercontinent that is referred to as Laurasia along with North and South China, while South America, Africa, India, Australia, and Antartica were joined together in the southern Gondwana.

Due to the formation of new coastlines with the birth of the new Atlantic, the once arid deserts became dominated by coastal rainforest and rich savannahs. With so much greenery to go around, it provided the perfect habitat for dinosaurs to become giants.

Late Jurassic Utah was not without its challenges though. Dry seasons were especially harsh with water being a scarce resource. Species that couldn't migrate were forced to congregate at ever shrinking pools of water, which could dry up completely in particularly bad seasons. These became hazardous as desperately thirsty animals would either find themselves trapped in thick mud to be preyed upon by predators, or just die from dehydration being unwilling to leave their water source.

The Cleveland-Quarry is one of these traps. Over time, the returning waters from the wet season would quickly bury dead carcasses and preserve them for generations to come. Allosaurus was a surprisingly common find here, probably attracted to the scent of rotting meat, with unlucky individuals becoming stuck as well.

It's among the specimens of Allosaurus that Stokesosaurus would be identified, likely drawn by the same desperation that spurned many a carnivore to their death.

Evolutionary History

Stokesosaurus clevandii is considered part of what is referred to as Pantyrannosauria: a group that is more advanced than the more primitive Proceratosaurs that includes Guanlong, an often-cited tyrannosaur ancestor. Proceratosaurs and early Pantyrannosaurs were small to medium-sized predators, often overshadowed by the larger allosaurs. Believed to have migrated to North America from Asia.

They in turn are members of the coelurosaur family that first evolved from around 160 million years ago. Coelurosaurs are dinosaurs that are most closely related to birds, such as dromaeosaurs and the tyrannosaurs themselves. Small and lightweight, they were able to feed primarily on small game and avoid direct competition with larger predators.

Description

What little we have of Stokesosaurus clevelandi (Stokes' Lizard of Cleveland) are mainly fragmentary remains. The most complete and intact specimen is UMNH 2938, which consists of a left hip bone. It's believed to belong to a juvenile, with the lower picture being scaled to a probable adult.

With an estimated length of 3 to 4 meters when fully grown, Stokesosaurus was a pint sized predator. Far smaller than the more famous giant herbivores that populated prehistoric Utah. This would've restricted its diet to smaller game such as rodents or young dinosaurs small enough to attack. To catch agile prey such as these, it's likely Stokesosaurus's light frame would've allowed it to be fast and agile themselves.

Being small and fast would also allow it to deal with the larger and more ferocious allosaurs. Stokesosaurus would've simply been too scrawny and small to make a proper meal out of, so they were more than likely not worth the effort needed by the larger predators to catch them. The most contact the two groups would've had would be during feedings where the smaller Stokesosaurus would easily be chased off by the larger allosaurs. Not before taking a few bites from the carcass themselves first of course.

Surviving Among Giants

Despite being in the low end of the food chain, there are certain advantages to being small. For starters, a small body mass requires less amounts of food to maintain. Meaning Stokesosaurus can afford to spend less time hunting and expending energy.

A lesser need for food also means a lesser need for territory and a steady supply of meat. Big predators often need wide territories in order to maintain their immense size. And with such a high demand in food and space, means competition for territory can be fierce and often dangerous. Small predators like Stokesosaurus avoid this problem by not having a need for such wide territories.

Life for a big predatory dinosaur was rough. Between having to hunt dangerous big game and contend with rivals for large territories, many large predatory dinosaur remains have evidence of injury. The famous Allosaurus specimen MOR 693 or "Big Al" was discovered to have evidence of 19 broken bones throughout his life, with signs of an illness being his cause of death. Stokesosaurus may have been able to avoid this fate by going after smaller game and having a reduced need for territory, thus reducing the threat of deadly competition. Living small and avoiding life threatening battles or hunts probably allowed Stokesaurus and other early tyrannosaurs to thrive under the shadows of giants. Until they were able to become the famous predators known the world over

Pop Culture

Stokesosaurus has a very minimal presence in media, though it does make a noticeable appearance in the Zoo Tycoon 2: Extinct Animals expansion pack. Players are able to adopt Stokesosaurus to add to their zoo as a 1 1/2 star animal. Here it has been beefed up in size to a medium sized carnivore with a large enclosure requirement and is treated as an apex predator similar to Tyrannosaurus rex.

There is also an easter egg of sorts related to Stokesosaurus. If a painting easel is placed within its enclosure as a toy, it'll put on a pair of glasses and paint on the easel, similar to an elephant.

Sources:

Jurassic Period - Geology Page

(PDF) The dinosaur death-trap of the Cleveland Lloyd Quarry, Emery County, Utah | ResearchGate

The phylogeny and evolutionary history of tyrannosauroid dinosaurs | Scientific Reports (nature.com)

Stokesosaurus (prehistoric-wildlife.com)

The Systematics of Late Jurassic Tyrannosauroid Theropods from Europe and North America

Review of Pathologies on MOR 693: An Allosaurus from the Late Jurassic of Wyoming and Implications for Understanding Allosaur Immune Systems

Artists

Stokesosaurus by Tom Parker from Wikipedia

Jurassic Period Paleogeography from Britannica

Cleveland-Lloyd Dinosaur Quarry by Mark Ostler from visitutah.com

Stokesosaurus clevelandi: Stokes' lizard by Paleonerd01 from deviantart

Stokesosaurus from prehistoric-wildlife.com

Evan Johnson-Ransom from twitter

Zoo Tycoon 2 pics taken from Zoo Tycoon wiki

[dinosaur-overlord-blog]

This is Nugget, he’s a Stokesosaurus. He’s a Carnivore, and would be smaller than a human.

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Dinosaur of the Day: Stokesosaurus clevelandi by Christopher252 Stokesosaurus "Stoke's Lizard" Family: Proceratosauridae: Time: Late Jurassic (150Ma) Location: Utah, USA Size (length): 2.5m

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Allosauroids: Keeping tyrannosauroids down and outcompeting non-spinosaurid megalosauroids since the mid-Jurassic. Inspired by paper-reading for a paper I'm writing.

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Skeletal drawing of Stokesosaurus clevelandi by Scott Hartman