Rechnisaurus is an extinct genus of dicynodont from the Middle Triassic (Anisian) Yerrapalli Formation of India. It contains a single species, Rechnisaurus cristarhynchus.^[1]

Rechnisaurus has had a long history of confusion with the far more widespread dicynodont Kannemeyeria. Rechnisaurus cristarhynchus was originally described as a new genus and species in 1970, on the basis of fossils from India. Later in the 1970s, additional specimens were found in Africa (namely the Ntawere Formation of Zambia and the Omingonde Formation of Namibia) and referred to the species. These African fossils were noted to be very similar to Kannemeyeria, so Rechnisaurus was renamed as a species of Kannemeyeria, Kannemeyeria cristarhynchus. However, in 1989 the original Indian fossils were re-compared to Kannemeyeria and found to be distinct, so Rechnisaurus was re-established in a more restricted sense including only the Indian fossils.^[2]

The African fossils continued to be designated as Kannemeyeria cristarhynchus, but this was later found to be untenable, since that species name was based on Rechnisaurus cristarhynchus, which had been established as a distinct genus. In 2003, the African species of Kannemeyeria was renamed to Kannemeyeria lophorhinus.^[3]

Rechnisaurus cristarhynchus has also been reported from the Manda Beds of Tanzania, though the Tanzanian fossils are in need of re-evaluation and are likely not related to Rechnisaurus. PVL 3963, a partial skull from the Quebrada de los Fosiles Formation of Argentina, was initially referred to Rechnisaurus and later designated as a new species of Kannemeyeria, under the species name Kannemeyeria aganosteus.^[2]

• The main groups of non-mammalian synapsids at Mikko's Phylogeny Archive

v t e Anomodontia
Kingdom: Animalia Phylum: Chordata Clade: Synapsida Clade: Therapsida Synapsida see Synapsida Anomodontia see below↓
Anomodontia Anomodontia Biseridens Novocynodon? Anomocephaloidea Anomocephalus Tiarajudens Venyukovioidea Otsheria Parasuminia Suminia Ulemica Venyukovia Chainosauria Galechirus Galeops Galepus Patranomodon Anomocephaloidea? Dicynodontia see below↓
Dicynodontia Dicynodontia Brachyprosopus Colobodectes Eodicynodon Lanthanostegus Nyaphulia Pristerodon Pylaecephalidae Diictodon Eosimops Prosictodon Robertia Endothiodontia Abajudon Endothiodon Niassodon Therochelonia Emydopoidea Digalodon Emydorhinus? Palemydops? Emydopidae Compsodon Emydops Myosauridae Myosauroides Myosaurus Kingoriidae Dicynodontoides Kombuisia Thliptosaurus Cistecephalidae Cistecephaloides Cistecephalus Kawingasaurus Kembawacela Sauroscaptor Bidentalia see below↓
Bidentalia Bidentalia Daqingshanodon Idelesaurus Keyseria Odontocyclops Rastodon Syops Elphidae Elph Interpresosaurus Katumbia Geikiidae Aulacephalodon Bulbasaurus Geikia Pelanomodon Oudenodontidae Australobarbarus Oudenodon Tropidostoma Rhachiocephalidae Kitchinganomodon Rhachiocephalus Dicynodontoidea Counillonia Daptocephalus Delectosaurus Dicynodon Dinanomodon Gordonia Kunpania Peramodon Repelinosaurus Taoheodon Turfanodon Vivaxosaurus Lystrosauridae Basilodon? Euptychognathus? Jimusaria? Kwazulusaurus Lystrosaurus Sintocephalus? Kannemeyeriiformes see below↓
Kannemeyeriiformes Kannemeyeriiformes Angonisaurus Dinodontosaurus Elephantosaurus Woznikella Shansiodontidae Shansiodon Tetragonias Vinceria Rhinodicynodon Kannemeyeriidae Acratophorus Dolichuranus Kannemeyeria Parakannemeyeria Rabidosaurus Rechnisaurus Rhadiodromus Shaanbeikannemeyeria Sinokannemeyeria Uralokannemeyeria Wadiasaurus Xiyukannemeyeria Stahleckeriidae Sungeodon Placeriinae Argodicynodon Lisowicia Moghreberia Pentasaurus Placerias Zambiasaurus Stahleckeriinae Eubrachiosaurus Ischigualastia Jachaleria Sangusaurus Stahleckeria Ufudocyclops
Other articles Nomina dubia Azarifeneria Baiopsis Calleonasus Chelyoposaurus Cristonasus Diaelurodon Dicranozygoma Elatosaurus Eurycarpus Haughtoniana Keirognathus Koupia Nasoplanites Opisthoctenodon Parvobestiola Planitorostris Platypodosaurus Putillosaurus Taognathus Paraphyletic groups Cryptodontia? Dromasauria