Heleosuchus
| Heleosuchus Temporal range:Late Permian
| |
|---|---|
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Neodiapsida |
| Genus: | †Heleosuchus Broom, 1907 |
| Species | |
|
Heleosaurus griesbachiOwen, 1876[1] | |
Heleosuchusis an extinctgenusof diapsid reptile from theLate PermianofSouth Africa.It was originally described as a species ofSaurosternonbyRichard Owen.Thetype speciesisSaurosternon griesbachi.The specific name honoursCarl Ludolf Griesbach.It was later recognized as a separate genus byRobert Broom.[2][3]
At one time, thetype specimenofHeleosuchuswas thought to be lost. However, it remains at theNatural History Museum, Vienna,where it is numbered NHMW 2374, while theNatural History Museum(formerly British Museum (Natural History)) possesses a cast numbered R. 5000. Several other casts of NHMW 2374 are present in several other European institutions, among them a cast of higher fidelity to the original.
While the type was thought to be lost,Susan E. Evansredescribed this taxon on the basis of an older mold which had been taken of the type specimen prior to its disappearance.[4]When the specimen appeared in later years, a higher quality mold was taken and described byRobert L. Carrollthat allowed a better description of this taxon.[3]
Heleosuchusis only known from the posterior half of the skull and a cervicodorsal column with some associated forearm elements and hindlimb elements. The hindlimbs are better preserved than the forearms.
Heleosuchusis suggested as being either an early diapsid reptile, not closely related to other lineages, or as being an aberrant and primitive lepidosauromorph.[3]Heleosuchusshares the hooked fifth metatarsal found in some other diapsids, such as primitive turtles (Odontochelys), lepidosauromorphs, and archosauromorphs, but it also resembles "younginiform" -grade diapsids in its gross morphology.[3]Heleosuchusmay also share a thyroid fenestra with these higher diapsid reptiles as well, but the identity of this feature is disputed.[3]
See also
[edit]
- Heleosaurus- BothHeleosaurusandHeleosuchuswere at one time thought to be diapsid reptiles.[5]
- Youngina-Heleosuchuswas once suggested as being a relative ofYoungina,[6]but this view has been summarily dismissed in subsequent literature (Carroll, 1987; Evans, 1984).
References
[edit]- ^Owen, R. 1876. "Descriptive and illustrated catalogue of the fossil Reptilia of South Africa in the collection of the British Museum." Trustees of the British Museum (Natural History), London, UK.
- ^Broom, R. (1913). "A revision of the reptiles of the Karroo".Annals of the South African Museum.7:361–366.
- ^abcdeCarroll, R. L. (1987). "Heleosuchus:an enigmatic diapsid reptile from the Late Permian or Early Triassic of southern Africa ".Canadian Journal of Earth Sciences.24(4): 664–667.Bibcode:1987CaJES..24..664C.doi:10.1139/e87-064.
- ^Evans, S. E. 1984. The anatomy of the Permian reptileHeleosuchus griesbachi.Neues Jahrbuch für Geologie und Paläontologie, Monatshefte,12: 717-727.
- ^Carroll, R. L. (1976). Eosuchians and the origin of archosaurs. In "Athlon essays on palaeontology in honour of Loris Shano Russell", C. S. Churcher (Ed.),Royal Ontario Museum,Life Sciences, Miscellaneous Publications, pp. 58-79.
- ^Carroll, R. L. 1981. Plesiosaur ancestors from the Upper Permian of Madagascar.Philosophical Transactions of the Royal Society of London, Series B: Biological Sciences,17: 500-511.
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