n. plTheriodontia(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.☞ They had biconcave vertebræ, ambulatory limbs, and a well-developed pelvis and shoulder girdle. Some of the species had large maxillary teeth. The head somewhat resembled that of a turtle. The Dicynodont is one of the best-known examples. See Dicynodont.
Century Dictionary and Cyclopedia
theriodontiaAn order of extinct Reptilia, so called from the resemblance of the dentition in some respects to that of mammals. There was in some forms a large laniariform canine tooth on each side of each jaw, separating definable incisors from the molar teeth. The head somewhat resembled a turtle's; the vertebræ were amphicœlous, the limbs ambulatory with well-developed pectoral and pelvic arches; the humerus had a supracondylar foramen. Many genera have been described from the Permian and Triassic of Africa, as Dicynodon, Cynodraco, Tigrisuchus, and Galesaurus. The original application of the term has been modified by subsequent discoveries; it has become an inexact synonym of Theromorpha, and has been used instead of Pelycosauria. Also Theriodonta and Therodontia. See cut under Dicynodon.
Webster's Revised Unabridged Dictionary
NL., fr. Gr. (dim. of a beast) + , , a tooth
The most interesting fact about the molar series in the Theriodontia is that we meet with the two types of molars that occur in the mammals.
"The Cambridge Natural History, Vol X., Mammalia" by Frank Evers Beddard