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 creatures were fast-moving predators, chasing down lizards and other small prey. They used their tails as counterweights when running, and the distinctive swish of the dinosaur's tail as it banked at speed was instantly recognisable. Compsognathus was one of the most common dinosaurs, with thousands of specimens scurrying through the undergrowth of Jurassic jungles. (PROSE: Prehistory Repeating Itself [+]Loading...["Prehistory Repeating Itself (feature)"])
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)