''Rhinesuchus'' (meaning "rasp crocodile" for the ridged surface texture on its skull bones) is a large

temnospondyl Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') or temnospondyls is a diverse ancient order (biology), order of small to giant tetrapods—often considered Labyrinth ...

. Remains of the genus are known from the

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

of the

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

Karoo The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe Khoemana (also known as !Orakobab or Korana) word is a semidesert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its extent is ...

Basin's ''Tapinocephalus'' and ''Cistecephalus'' assemblage zones, both belonging to the

Beaufort Group The Beaufort Group is the third of the main subdivisions of the Karoo Supergroup in South Africa. It is composed of a lower Adelaide Subgroup and an upper Tarkastad Subgroup. It follows conformably after the Ecca Group and unconformably under ...

. The skull of ''Rhinesuchus'' had a flat triangular shape with blunt snout similar to some of the other large temnospondyls, and had a

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sep ...

filled with small sharp teeth, suggesting that it hunted fish. Also, the small eyes were on top of the head suggesting that it approached its prey from below.

Etymology

The name ''Rhinesuchus'' comes from Greek ῥίνη (''rhinē'') "file, rasp" plus σούχος (''soukhos'') "crocodile" for the skull surface texture: "The upper cranial bones are ornamented by a rather fine reticulation of sharp ridges". (The name does not mean "nose crocodile" (as if from Greek ''rhis, rhinos'' "nose") or refer to the Rhine River in Germany.)

Description

''Rhinesuchus whaitsi'' probably reached a mass of 100 kg. Counts of lines of arrested growth (LAG) indicate that like many amphibians, ''Rhinesuchus'' grew seasonally and was able to live more than 30 years. They also indicate that ''Rhinesuchus'' was able to sustain prolonged periods of stress, either climatic or nutritional, and that portions of its skeleton may have experienced more sustained growth.

Taxonomy

The type species is ''Rhinesuchus whaitsi''. Two more species, ''R. africanus'' and ''R. wadiai'', are considered to be ''

nomina dubia In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

''. ''R. broomianus'' and ''R. beaufortensis'' have been synonymized with ''R. whaitsi'', while ''R. capensis'' has been moved out of the genus into '' Rhinesuchoides''. ''Muchocephalus'' has also been synonymized with ''R. whaitsi''. ''Rhinesuchus major'' (Broom, 1911) from the Free State was later synonymized with '' Uranocentrodon senekalensis''. The first rhinesuchid from outside southern Africa was described as ''Rhinesuchus wolgodvinensis'' (Yacovlev, 1916). The specimen, collected from Early Triassic beds from Russia, was considered the first ''Rhinesuchus'' from the Triassic, although currently it is considered, instead, a wetlugasaurid.

Etymology

Description

Taxonomy

References

Further reading