Drepanosaurus

Drepanosaurus is a genus of arboreal (tree-dwelling) reptile that lived during the Triassic Period. Only one specimen of Drepanosaurus has thus far been found. This specimen was incomplete and lacked a head and neck. Drepanosaurus was probably an insectivore, and lived in a coastal environment in what is now modern Italy.

Anatomy
A full sized adult Drepanosaurus had a length of about half a meter.[citation needed] Its name means "scythe lizard", which is thought to refer either to the enlarged claw on its forelimb, or the claw-like structure at the tip of its prehensile tail. The structure at the end of the tail is made of fused vertebrae.[citation needed]

The forelimb of Drepanosaurus is highly modified compared to other vertebrates and very robust.[citation needed] Its ulna was altered from being a forearm bone into an odd crescent shaped site for muscle attachment.[citation needed] The role played by the ulna in most tetrapods is replaced by an elongated carpal bone.[citation needed] Additional musculature would be attached to the high withers that characterized Drepanosaurus and its close relatives.[citation needed]

A clue to the purpose of these large muscles can be found on its hand. The animal's "index finger" bore a large claw reminiscent of those born by dinosaurs such as Noasaurus and Baryonyx. However it is more likely that Drepanosaurus used its claw like the modern pygmy anteater, tearing through bark and insect nests to find invertebrate prey.[citation needed] Some researchers have forwarded the more far-fetched proposal that the claw was used to excavate burrows, but this is unlikely.