theriodontia

from The Century Dictionary.

• An order of extinct Reptilia, so called from the resemblance of the dentition in some respects to that of mammals.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Paleon.) An extinct order of reptiles found in the Permian and Triassic formations in South Africa. In some respects they resembled carnivorous mammals. Called also Theromorpha.