Prehistoric Models: Therapsids
Therapsida is a large group of synapsids (formerly called “mammal like reptiles”) which include the ancestors of modern mammals. They were the dominant terrestrial vertebrates from the middle/late Permian to the early Triassic. The most well known of this group are the saber toothed Gorgonopsia (gorgons for short).
Kingdom: Animalia – Phylum: Chordata – Superclass: Tetrapoda – Clade: Synapsida – Clade: Therapsida – Clade: Neotherapsida – Clade: Theriodontia – Clade: Gorgonopsia
(“gorgons”)
Middle Permian to Late Permian

Genus: Lycaenops ”Wolf face”.
Genus pronounced: Ly-can-ops.
Named By: Robert Broom - 1925.
Species: L. ornatus (type), L. minor, L. ornatus, L. quadrata, L. sollasi, L. tenuirostris.
Classification: Clade: Synapsida – Clade: Therapsida – Clade: Gorgonopsia
Known locations: South Africa.
Time period: Permian (Wuchiapingian).
Diet: Carnivore.
Size: 1 meter long.

Genus: Dinogorgon ”Terrible Gorgon”.
Genus pronounced: Dy-noe-gor-gon.
Named By: Robert Broom – 1936.
Species: D. rubidgei (type), D. pricei, D. quinquemolaris.
Classification: Clade: Synapsida – Clade: Therapsida – Clade: Gorgonopsia
Known locations: Tanzania and South Africa.
Time period: Permian (Wuchiapingian).
Diet: Carnivore.
Size: 2 meters long.

Genus: Inostrancevia ”After Aleksandr Inostrantsev”.
Genus pronounced: In-oh-stran-see-ve-ah.
Named By: Vladimir P. Amalitsky - 1922.
Species: I. alexandri (type), I. latifrons, I. uralensis.
Classification: Clade: Synapsida – Clade: Therapsida – Clade: Gorgonopsia
Known locations: Russia.
Time period: Permian (Wuchiapingian).
Diet: Carnivore.
Size: 3.5 meters long.
Kingdom: Animalia – Phylum: Chordata – Superclass: Tetrapoda – Clade: Synapsida – Clade: Therapsida – Clade: Eutheriodontia – Suborder: Therocephalia – Family: Trochosuchidae
(lycosuchidae)
Middle Permian

Genus: Trochosaurus.
Genus pronounced: Tro-ko-sore-us.
Named By: Haughton 1915.
Species: T. acutus (type).
Classification: Clade: Synapsida – Clade: Therapsida – Family: Trochosuchidae.
Known locations: South Africa.
Time period: Permian.
Diet: Carnivore.
Size: Unavailable.
Kingdom: Animalia – Phylum: Chordata – Superclass: Tetrapoda – Clade: Synapsida – Clade: Therapsida – Clade: Eutheriodontia – Clade: Cynodontia – Clade: Cynognathia – Family: Cynognathidae
(cynognathians “dog jaw”)
Early to late Triassic

Genus: Cynognathus “Dog jaw”.
Genus pronounced: Sy-noe-nay-fuss.
Named By: Harry Govier Seeley - 1895.
Species: C. crateronotus (type), C. seeleyi.
Classification: Clade: Synapsida – Clade: Therapsida – Family Cynognathia
Known locations: Antarctica, Argentina, China, South Africa.
Time period: Triassic (Anisian).
Diet: Carnivore.
Size: 1 meter long.

Genus: Cynognathus “Dog jaw”.
Genus pronounced: Sy-noe-nay-fuss.
Named By: Harry Govier Seeley - 1895.
Species: C. crateronotus (type), C. seeleyi.
Classification: Clade: Synapsida – Clade: Therapsida – Family Cynognathia
Known locations: Antarctica, Argentina, China, South Africa.
Time period: Triassic (Anisian).
Diet: Carnivore.
Size: 1 meter long.
Kingdom: Animalia – Phylum: Chordata – Superclass: Tetrapoda – Clade: Synapsida – Clade: Therapsida – Suborder: Anomodontia – Clade: Chainosauria – Clade: Dicynodontia
(dicynodonts “two dog tooth”)
Middle Permian to Late Triassic

Genus: Dicynodon ”Two dog teeth”.
Genus pronounced: Die-cy-no-don.
Named By: Richard Owen - 1845.
Classification: Family: Dicynodontidae.
Species: D. lacerticeps (type), D. angielczyki, D. bolorhinus, D. leoniceps, D. leontops, D. lissops, D. osborni, D. plateceps, D. trautscholdi, D. whaitsi.
Known locations: China, Russia, South Africa, Tanzania.
Time period: Late Permian (Changhsingian).
Diet: Herbivore.
Size: Average 1.2 meters long, but some variation between species.

Genus: Placerias “Broad body”.
Genus pronounced: Plah-see-ree-ass.
Named By: Lucas – 1904.
Classification: Family: Kannemeyeriidae.
Species: P. gigas, P. gigus, P. hesternus.
Known locations: USA, Arizona.
Time period: Triassic (Carnian to Norian).
Type: Herbivore.
Size: Up to 3.5 meters long.

Genus: Kannemeyeria ”From Kanne”.
Genus pronounced: Kan-eh-my-air-ee-ah.
Named By: Harry Govier Seeley - 1908.
Classification: Family: Kannemeyeriidae.
Species: K. simocephalus (type), K. aganosteus, K. lophorhinus.
Known locations: Africa, Asia, India, South America.
Time period: Triassic (Olenekian to Anisian).
Diet: Herbivore.
Size: 3 meters long.

Genus: Lystrosaurus “Shovel lizard”.
Genus pronounced: Liss-tro-sore-us.
Named By: Edward Drinker Cope - 1870.
Classification: Family: Lystrosauridae.
Species: L. murrayi (type), L. declivus, L. curvatus, L. maccaigi, L. georgi.
Known locations: Widespread across southern continents with the main concentration of remains found in South Africa. Other specimens have been recovered from Antarctica, China, India, Mongolia and Russia.
Time period: Late Permian to the Early Triassic.
Type: Herbivore.
Size: Between 0.6 and 2.5 meters long depending upon the species. Average about 0.9 meters long.
Kingdom: Animalia – Phylum: Chordata – Superclass: Tetrapoda – Clade: Synapsida – Clade: Therapsida – Suborder: Dinocephalia
(dinocephalians “terrible heads”)
Early to Middle Permian

Genus: Estemmenosuchus ”Crowned crocodile”.
Genus pronounced: Ess-teh-men-oh-soo-kuss.
Named By: Chudinov - 1960.
Classification: Clade: Synapsida – Clade: Therapsida – Suborder: Dinocephalia – Family: Estemmenosuchidae.
Species: E. uralensis, (type) E. mirabilis.
Known locations: Russia, Perm region.
Time period: Permian (Wordian).
Diet: Herbivore.
Size: E. uralensis about 4.5 meters long, E. mirabilis about 3 meters long.
