Compsognathus

The Compsognathus was a type of theropod dinosaur. They were small, no larger than a turkey, and were mainly scavengers.

Indeed, when showing one of his companions a Compsognathus during a trip back in time 150 million years, the Fourth Doctor suggested the Compsognathus might have been the smallest Dinosaur ever. (PROSE: The Doctor Who Dinosaur Book)

The compsognathus was one of the species that the Silurians brought back from extinction after they took over in a parallel world. Compsognathuses would scavenge from the humans and their settlements. While searching for medicine in 1993, Ace, Benton, Jan, Julia and Alan were followed by a compsognathus, which Ace unofficially adopted as a mascot and named after Benton. She later chased it off after it was found scavenging one of their dead horses. (PROSE: Blood Heat)