Calleonasus | |
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Genus: | Calleonasus |
Calleonasus is an extinct genus of non-mammalian synapsid from the Anisian Donguz Formation of Russia.
Synapsids are a group of animals that includes mammals and every animal more closely related to mammals than to the other members of the amniote clade, such as reptiles and birds. Unlike other amniotes, they have a temporal fenestra, an opening low in the skull roof behind each eye, leaving a bony arch beneath each; this accounts for their name. Primitive synapsids are usually called pelycosaurs or pelycosaur-grade synapsids. This informal term consists of all synapsids that are not therapsids, a monophyletic, more advanced, mammal-like group. The non-mammalian synapsids were described as mammal-like reptiles in classical systematics, but this misleading terminology is no longer in use as synapsids as a whole are no longer considered reptiles. They are now more correctly referred to as stem mammals or proto-mammals.
Driveria is an extinct genus of non-mammalian synapsids the Lower Permian of San Angelo Formation, Texas.
Cryptocynodon is an extinct genus of non-mammalian synapsid from the Cistecephalus Assemblage Zone of the Beaufort Group in South Africa,
Eurychororhinus is an extinct genus of non-mammalian synapsid.
Eosyodon is an extinct genus of non-mammalian synapsids from the San Angelo Formation.
Emyduranus is an extinct genus of non-mammalian synapsid from the Permian Cistecephalus Assemblage Zone and the Teekloof Formation of the Beaufort Group, South Africa.
Elatosaurus is an extinct genus of non-mammalian synapsid.
Ictidostoma is an extinct genus of non-mammalian synapsids known from the Tropidostoma Assemblage Zone.
Koupia is an extinct genus of non-mammalian synapsid.
Lanthanostegus is an extinct genus of non-mammalian synapsids from the Capitanian Tapinocephalus Assemblage Zone, Koonap Formation of South Africa.
Milosaurus is an extinct genus of non-mammalian synapsids native to Illinois that was alive during the latest Carboniferous and earliest Permian. It was named in 1970 on the basis of FMNH 701, a partial skeleton.
Nitosaurus is an extinct genus of non-mammalian synapsids.
Scalopolacerta is an extinct genus of non-mammalian synapsids.
Rhinodicynodon is an extinct genus of non-mammalian synapsid of the Middle Triassic (Anisian) Donguz Formation of European Russia.
Rechnisaurus is an extinct genus of non-mammalian synapsid from the Middle Triassic (Anisian) Yerrapalli Formation of India.
Trichasaurus is an extinct genus of non-mammalian synapsids.
Traversodontoides is an extinct genus of non-mammalian synapsids.
Synostocephalus is an extinct genus of non-mammalian synapsid.
Stereophallodon is an extinct genus of non-mammalian synapsids.
Uralokannemeyeria is an extinct genus of non-mammalian synapsid.