April 4, 2022 Scott Kraus

Allosaurus – The Commonly Overlooked Carnivore

Named with the Grecian term meaning “different lizard,” Allosaurus perplexed archeologists with a unique bone structure and vertebrae pattern. It’s for this difference and the debate those differences provoked that many paleontologists opted out of further discovery and discussion of this particular dinosaur. Classified as simply “a huge carnivore,” Allosaurus research fell to the knowledge of few remaining paleontologists, making the dinosaur one of science’s most overlooked creatures.

Quick Facts

What Did Allosaurus Look Like?

Allosaurus Was A Jurassic Period Meat-Eater

Referred to as the “Great Great Grandfather” of the T-Rex, Allosaurus was supposedly far more frightening and vicious. This carnivorous dinosaur of the late Jurassic period feasted on large meat-eaters; however, these were eaten in different ways than that of a normal meat eating dinosaur of this time. Instead of directly tearing chunks from an herbivore’s hide, this giant predator would rip into it’s prey — shaking it’s head from side to side violently and often embedding teeth into the herbivore’s bones. Numerous plant-eater fossils have been discovered with Allosaurus teeth firmly immortalized in the fossilized remains.

Physical Attributes of Allosaurus

Allosaurus was a powerful predator; a fact that was made prevalent with the length of 2 trunk-like legs, rippled with muscle. The vertebrae of this Jurassic beast was unlike the spine of any other dinosaur – hence a name that means “different lizard.” Shaped much like it’s later carnivorous cousin, T-Rex, these beasts had S-shaped necks that extended from bulky midsection. Their bones were especially heavy – leading down from a chunky torso to a thick tail, built for the purpose of defense and destruction.

The Allosaurus had what scientists deemed “Gastralia” — translating to ‘hanging belly ribs.’ Instead of being attached to the spinal column, these ribs grew to the skin around the dinosaur’s abdomen. Their purpose was to support the internal organs, which were especially delicate and prone to fatal injury if the Allosaurus took a tumble while pursing prey.

The Teeth of Allosaurus

Allosaurus teeth were similar to modern serrated blades, with a length of up to 4 inches per tooth. The average count of a dinosaur’s teeth was between 14 and 17 — however, Allosaurus was a creature of renewal. Much like a shark, these dinosaurs would constantly shed their teeth in exchange for newer, sharper ones.

Archeologists have found countless Allosaurus teeth due to the fact that these dinosaur were always losing and replacing theirs. One interesting tidbit about Allosaurus teeth regards their shape — towards the front, their teeth were almost completely straight, but their teeth started curving inwards towards the back. This indicates that the straighter teeth were meant to hold the prey, while the curvier teeth did the work hooking the most chunks of meat.

Allosaurus In Pop-Culture

Allosaurus bones have been unearthed around areas of Western North America for over a century, making this dinosaur one of the best examples of a dominant species. They were everywhere! Popular culture has made the Allosaurus almost as popular and well-known as the T-Rex. Film adaptations, fictitious novels, and kid-friendly dino books began appearing around 1912, beginning with the predatory story of the Allosaurus in Arthur Conan Doyle’s The Lost World.

Most recently, the BBC and Discovery channels composed specials entitled The Ballad of Big Al and Dinosaur Revolution. The television shows presented realistic evidence of the existence of Allosaurus, complete with information on fossils and finds. The evidence was then followed up with theories and speculations, discussing the habits of living Allosaurus and extinction possibilities based on the injuries prevalent on “Big Al’s” bones.

What Did Allosaurus Eat?

Bluntly, Allosaurus ate whatever wasn’t fast enough to get away. As a fierce and vicious carnivore, these dinosaurs are speculated to have eaten their own young if the mood struck them. When a dinosaur is cannibalistic, you can bet the rest of their menu selection is nondiscriminatory. As long as that night’s dinner item had meat attached, this predator probably had no qualms about eating it.

How Did Allosaurus Move?

Like the overrated T-Rex, the Allosaurus had powerful legs and smaller arms. This means they relied mostly on their toe-claws for running and grasping at food as they pursued it — putting a damper on their speed. It’s been estimated that larger carnivores could reach their top gait of 12-13 mph. Unfortunately, this wouldn’t last long as their massive bulk made it hard for them to maintain this velocity for long periods of time — the main reason their prey was often smaller and much slower than them.

Predators & Prey of Allosaurus

As stated before, the Allosaurus had few predators, but plenty of prey. Albeit, there is one dinosaur this beast had to live in the same environment with — one that wasn’t a predator but intimidated the Allosaurus with sheer size and defense weaponry. The Stegosaurus! The steel plated amour and spiked tail of the Stegosaurus made it an unappetizing option for the Allosaurus.

It’s believed that the Allosaurus would have only attacked the Stegosaurus if there were absolutely no other prey-options available at the time. Otherwise, these dinosaurs would have not dared to take on a fully grown Stegosaurus on their own. It’s uncertain whether Allosaurus hunted in packs — but if they did, it would have been an easier but still a very difficult feat to take down one of those massive herbivores.

The Discovery of Allosaurus

Where Did Allosaurus Live?

Allosaurus fossils were discovered in several areas of western North America, mainly in what would have been dry climates in the Jurassic period. The most notable discovery of a large quantity of Allosaurus fossils have been found in a quarry in Utah; therefore, it’s believed that these dinosaurs favored woodlands and desert-like plains.

Allosaurus Specimen Discovery

The discovery of Allosaurus is rife with controversy because no one knows exactly when the first specimen was obtained. There are several paleontologists and archeologists who have deemed the Allosaurus fossils their own; however, the one on the forefront of the discovery was Othniel C. Marsh. While this paleontologist didn’t unearth many new specimens of the Allosaurus, he was the first to coin it’s name and give the dinosaur an identity with the bones that had already been discovered.

It wasn’t until 1883, an entire 6 years after Marsh named Allosaurus, that a rancher in Colorado uncovered a complete Allosaurus skeleton, although deteriorated and in poor condition. Further investigation around that area led to the discovery of several more Allosaurus fossils, ranging from juvenile to adult. Yet, these still weren’t the most significant fossilized finds regarding the Allosaurus.

In 1991, researchers unearthed an Allosaurus skeleton that had been perfectly preserved by the sands and compact dirt of Wyoming. Judging by an analysis of the Allosaurus bones, the fossils were from a teenaged dinosaur who had taken quite a few tumbles. Inevitably, that particular Allosaurus had fallen prey to bacterial infections caused by his latest hard falls. The fossil was 26-foot-long and an estimated 95% finished with growth when tragedy struck. Dubbed “Big Al,” the fossils are now on display in a museum near the Wyoming area where it had been originally uncovered.

The Significance of Allosaurus

Allosaurus is a popular and often-mistaken dinosaur; the subject of many an archeological discussion and debate between scientists. The discovery of ‘Big Al’ allowed researchers to speculate about injury and why these dinosaurs may have gone extinct — besides the meteorite theory. Allosaurus remains one of the most studied dinosaurs, as researchers continue to find sub-species and descendants of the original dinosaurs all the time.