''Rechnisaurus'' is an extinct
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
dicynodont
Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivores that typically bore a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, t ...
from the
Middle Triassic
In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is di ...
(
Anisian
In the geologic timescale, the Anisian is the lower stage (stratigraphy), stage or earliest geologic age, age of the Middle Triassic series (stratigraphy), series or geologic epoch, epoch and lasted from million years ago until million years ag ...
)
Yerrapalli Formation
The Yerrapalli Formation is a Triassic rock formation consisting primarily of mudstones that outcrops in the Pranhita–Godavari Basin in southeastern India. The Yerrapalli Formation preserves fossils of freshwater and terrestrial vertebrates a ...
of
India
India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...
. It contains a single species, ''Rechnisaurus cristarhynchus''.
History
''Rechnisaurus'' has had a long history of confusion with the far more widespread dicynodont ''
Kannemeyeria
''Kannemeyeria'' is a genus of dicynodont that lived during the Anisian age of Middle Triassic period in what is now Africa and South America. The generic name is given in honor of Daniel Rossouw Kannemeyer, the South African fossil collector w ...
''. ''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
The Ntawere Formation is a Middle Triassic (Anisian) geological formation in Zambia, preserving fossils of synapsids, archosaurs, and temnospondyls.
Geology
Several different facies are present in the Ntawere Formation, reconstructing a floodpl ...
of
Zambia
Zambia, officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa. It is typically referred to being in South-Central Africa or Southern Africa. It is bor ...
and the
Omingonde Formation
The Omingonde Formation is an Early Triassic, Early to Middle Triassic (Anisian to Ladinian) geologic Formation (geology), formation, part of the Karoo Supergroup, in the western Otjozondjupa Region and northeastern Erongo Region of north-central N ...
of
Namibia
Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...
) 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.
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''.
''Rechnisaurus cristarhynchus'' has also been reported from the
Manda Beds
The Manda Formation (also known as the Manda Beds) is a Middle Triassic (Anisian?) or possibly Late Triassic (Carnian?) geologic formation in Tanzania. It preserves fossils of many terrestrial vertebrates from the Triassic, including some of the e ...
of
Tanzania
Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...
, 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
Quebrada may refer to:
Places Argentina
* Quebrada de Las Flechas, a valley in the province of Salta in northern Argentina
* Quebrada de Humahuaca, World Heritage, a valley in the province of Jujuy in northern Argentina
* Quebrada de Luna, vill ...
of
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
, was initially referred to ''Rechnisaurus'' and later designated as a new species of ''Kannemeyeria'', under the species name ''Kannemeyeria aganosteus''.
References
The main groups of non-mammalian synapsids at Mikko's Phylogeny Archive
{{Taxonbar, from=Q7302417
Kannemeyeriiformes
Prehistoric synapsids of Asia
Fossil taxa described in 1970
Anomodont genera