prescription drug neurontin 600 mg Name Meaning: Reaper Lizard

San Leonardo Geologic Era: Late Cretaceous

Nizip Location Found: Mongolia (specimen is a cast)

Uster Size: 8-9 meters long, 5.5 meters tall

Estimated Range: Modern Mongolia/China

Extinction: 70 million years ago

Imagine claws like this one attached to the hand of a dinosaur standing roughly two stories tall, and the claws would be around half the length of your body. That would be the reality if Therizinosaurus was standing in front of you. You probably wouldn’t have much to be afraid of, however. Based on the remains of Therizinosaurus’ close relatives, it was probably an herbivore.

To date, no complete therizinosaur of any kind has been found, but enough pieces and parts of various genera have been recovered that a reasonable guess can be made as to their appearance. The closest to a complete therizinosaur is Alxasaurus, which is still a composited animal (multiple individuals were found together). Despite the trend of most theropods being carnivores, Therizinosaurus and its relatives were herbivores, and strangely built ones at that.

Like many types of Cretaceous dinosaur, therizinosaurs started by being relatively small, only attaining the gigantic proportions of Therizinosaurus toward the end of the Cretaceous period. Tyrannosaurs underwent a similar change in size, as did hadrosaurs. Analysis of the braincase of a species related to Therizinosaurus shows they had a good sense of balance, hearing, and smell. This would have been useful in finding food or fending off predators, of which two very large ones, Alioramus and Tarbosaurus, existed at the same time.

The therizinosaur family was formerly called segnosaurs, after a previously discovered animal, Segnosaurus. Later analysis showed that they were the same type of animas, and not the prosauropod-like creatures that Segnosaurus is frequently depicted as. Since then, Segnosaurus has been reclassified as a therizinosaur, and the group segnosaurid is considered obsolete.

Image Credits:

Life Restoration: By Nobu Tamura –, CC BY-SA 4.0,

Therizinosaur Skeletons: By Jaime A. Headden (User:Qilong) –, CC BY 3.0,