Torvosaurus

“Savage Lizard”: Origin of the Name and History of Discovery

Discovery Starting from a Massive Claw

The discovery of Torvosaurus began with a single massive “thumb claw” found in Colorado, USA, in 1971.
Following extensive excavation surveys, it was described as a new species in 1979 and named “Torvosaurus tanneri,” combining the Latin words for “Savage” (Torvus) and “Lizard” (Saurus).

A New Species Dedicated to Dinotopia

In the 2000s, fossils were also discovered in Portugal, leading to the naming of a new species, “Torvosaurus gurneyi.”
This specific name was dedicated to James Gurney, the author of the picture book series Dinotopia, in which humans and dinosaurs coexist.

Surpassing Allosaurus? One of the Greatest “Powers” of the Jurassic

Overwhelming Size

Estimated to be 8 to 10 meters long and weighing 3 to 5 tons, it was one of the largest theropods of its time.
If specimens like “Edmarka,” which were once considered separate species, are indeed the same species, some Torvosaurus individuals may have boasted a size comparable to the later Tyrannosaurus.

“Jaws” and “Fangs” Specialized for Destruction

Its most distinctive feature was its massive head, reaching about 1.2 meters in length, and its ferocious teeth.

Massive head reaching about 1.2m in length and ferocious teeth

Its mouth was lined with sharp teeth about three times longer than those of the contemporaneous Allosaurus.
While Allosaurus sliced through flesh, the teeth of Torvosaurus possessed destructive power like “stakes” capable of crushing prey, bones and all.

Muscular Upper Arms

The upper arms of its forelimbs were extremely muscular, and the first finger (thumb) bore a massive hook-like claw.
This was a powerful weapon used to hold down and tear apart prey.

Allosaurus of “Technique” vs. Torvosaurus of “Power”

In Late Jurassic North America, two titans, Allosaurus and Torvosaurus, coexisted.
How did they share their habitat?

Differences in Hunting Styles

The decisive difference between the two lay in their “tactics.”

Allosaurus (Hunter of Technique)

Fast-footed, using long arms and claws to grapple with prey and slice them. They moved around a wide area.

Torvosaurus (Hunter of Power)

Slower-footed, but used their massive, solid bodies and overwhelming jaw power to deliver fatal blows (“one-hit kills”).

Possibility of Direct Confrontation

It is believed that Torvosaurus targeted slow-moving sauropodomorphs, hard prey like turtles, or carrion.
Although they basically occupied different niches, there are instances where Torvosaurus bite marks have been found on Allosaurus fossils. At times, acting as a “shadow ruler,” they may have intimidated and overwhelmed Allosaurus over prey.

A Primitive but Powerful Lineage: Megalosauridae

Lineage of Heavy Tanks

Taxonomically, they do not belong to the Allosaurs, but to the more primitive “Megalosauridae” (Spinosauroidea).
They were like “heavy tanks” that evolved independently during the Jurassic.

Discovery of Eggs

Fossilized eggs have also been discovered in Portugal, revealing that they were oviparous animals that laid eggs with a single-layered shell structure.
Whether they guarded their eggs like modern crocodiles or raised their young like birds awaits future research.