Eryops
Eryops was a genus native to Earth that lived in the Devonian period, over four hundred million years ago. The Eryops is believed to be the last common ancestor of cold-blooded and warm-blooded organisms. (VOY: "Distant Origin")
The Eryops that appeared in "Distant Origin" more closely resembles the Gorgonops, a type of synapsid, which were the ancestors of mammals, not dinosaurs. Also, Eryops lived in the Permian period, not the Devonian.