Science, Tech, Math › Animals & Nature Cynognathus Facts and Figures Share Flipboard Email Print John Cummings/Wikimedia Commons/CC BY 3.0 Animals & Nature Dinosaurs Carnivores Basics Paleontologists Dinosaurs & Birds Herbivores Marine Reptiles Prehistoric Mammals Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Forestry Evolution View More By Bob Strauss Science Writer B.S., Cornell University Bob Strauss is a science writer and the author of several books, including "The Big Book of What, How and Why" and "A Field Guide to the Dinosaurs of North America." our editorial process Bob Strauss Updated January 05, 2020 Name: Cynognathus (Greek for "dog jaw"); pronounced sigh-NOG-nah-thusHabitat: Woodlands of South America, South Africa, and AntarcticaHistorical Period: Middle Triassic (245-230 million years ago)Size and Weight: About three feet long and 10-15 poundsDiet: MeatDistinguishing Characteristics: Dog-like appearance; possible hair and warm-blooded metabolism About Cynognathus One of the most fascinating of all prehistoric creatures, Cynognathus may have been the most mammalian of all the so-called "mammal-like reptiles" (technically known as therapsids) of the middle Triassic period. Technically classified as a "cynodont," or dog-toothed, therapsid, Cynognathus was a fast, fierce predator, much like a smaller, sleeker version of a modern wolf. Clearly it thrived in its evolutionary niche since its remains have been discovered on no less than three continents, Africa, South America and Antarctica (which were all part of the giant landmass Pangea during the early Mesozoic Era). Given its wide distribution, you may be surprised to learn that the genus Cynognathus includes only one valid species, C. crateronotus, named by the English paleontologist Harry Seeley in 1895. However, in the century since its discovery, this therapsid has been known by no less than eight different genus names: besides Cynognathus, paleontologists have also referred to Cistecynodon, Cynidiognathus, Cynogomphius, Lycaenognathus, Lycochampsa, Nythosaurus and Karoomys! Further complicating matters (or simplifying them, depending on your perspective), Cynognathus is the only identified member of its taxonomic family, the "cynognathidae." The most interesting thing about Cynognathus is that it possessed many features normally associated with the first prehistoric mammals (which evolved from therapsids tens of millions of years later, during the late Triassic period). Paleontologists believe Cynognathus sported a thick coat of hair and may have given birth to live young (rather than laying eggs, like most reptiles); we know for a fact that it possessed a very mammal-like diaphragm, which enabled it to breathe more efficiently. Most startlingly, evidence points to Cynognathus having a warm-blooded, "mammalian" metabolism, quite unlike most of the cold-blooded reptiles of its day.