Wednesday, December 1, 2010

"Likhoelesaurus" the mysterious African nomen nudum

Quick update before an important post...

"Likhoelesaurus" Ellenberger, 1970
"L. ingens" Ellenberger, 1970
= "Likhoelesaurus ferox" Ellenberger, 1972
Norian, Late Triassic
Lower Elliot Formation, Lesotho
Material
- five teeth (70 mm)

Comments- Ellenberger and Ginsberg (1966) mentioned carnivorous dinosaur teeth from the Lower Elliot Formation, which were later called "Likhoelesaurus ingens" by Ellenberger (1970) and referred to Ornithosuchidae. These were not described properly though, making the name a nomen nudum. Ellenberger (1972) referred to "Likhoelesaurus ferox" as a "giant carnosaur" from zone A/5 of his lower red beds, illustrating five associated recurved teeth in a plate. This was another nomen nudum, with no explanation of the different species name (it may involve Basutodon ferox, but even if "Likhoelesaurus" were officially named, Basutodon would have priority). Kitching and Raath (1984) suggested it may be a junior synonym of Basutodon ferox. It was listed as a teratosaurid theropod by Chure and McIntosh (1989) and a melanorosaurid by Olshevsky (1991). Glut (1997) listed it as ?Theropoda incertae sedis, listed "?bones" among the remains and stated the teeth were 70 mm long. Knoll (2004) discusses the material under Rauisuchia, but notes it could be theropod as well.

Presumably the type material of "Likhoelesaurus ingens", from Ellenberger (1972).

With no published description, and only one undetailed photograph, the phylogenetic position of "Likhoelesaurus" remains uncertain. While their recurved morphology excludes referral to Melanorosauridae or any other sauropodomorph clade, differences between the teeth of carnivorous dinosaurs, crutotarsans (including ornithosuchids and teratosaurs) and other carnivorous archosauriforms have yet to be studied. Indeed, they are only assumed to be archosauriform here due to past identifications, since the presence of serrations has not been confirmed.  Synonymy with Basutodon is possible, but no shared derived characters have been suggested, Basutodon itself is probably undiagnostic and multiple archosauriform taxa are known from other Late Triassic localities.

References- Ellenberger and Ginsberg, 1966. Le gisement de Dinosauriens triasiques de Maphutseng (Basutoland) et l'origine des Sauropodes [The Triassic dinosaur locality of Maphutseng (Basutoland) and the origin of sauropods]. Comptes Rendus de l'Académie des Sciences à Paris, Série D. 262, 444-447.

Ellenberger, 1970. Les niveaux paléontologiques de première apparition des mammifères primoridaux en Afrique du Sud et leur ichnologie. Establissement de zones stratigraphiques detaillees dans le Stormberg du Lesotho (Afrique du Sud) (Trias Supérieur à Jurassique) [The paleontological levels of the first appearance of primordial mammals in southern Africa and their ichnology. Establishment of detailed stratigraphic zones in the Stormberg of Lesotho (southern Africa) (Upper Triassic to Jurassic). in Haughton (ed.). Second Symposium on Gondwana Stratigraphy and Paleontology, International Union of Geological Sciences. Council for Scientific and Industrial Research, Pretoria. 343-370.

Ellenberger, 1972. Contribution à la classification des Pistes de Vertébrés du Trias: Les types du Stormberg d'Afrique du Sud (I). Palaeovertebrata. 104, 152 pp.

Kitching and Raath, 1984. Fossils from the Elliot and Clarens Formations (Karoo Sequence) of the Northeastern Cape, Orange Free State and Lesotho, and a suggested biozonation based on tetrapods. Palaeontologia Africana. 25, 111-125.

Chure and McIntosh, 1989. A Bibliography of the Dinosauria (Exclusive of the Aves) 1677-1986. Museum of Western Colorado Paleontology Series #1. 226 pp.

Olshevsky, 1991. A Revision of the Parainfraclass Archosauria Cope, 1869, Excluding the Advanced Crocodylia. Mesozoic Meanderings. 2, 196 pp.

Glut, 1997. Dinosaurs - The Encyclopedia. McFarland Press, Jefferson, NC. 1076 pp.

Knoll, 2004. Review of the tetrapod fauna of the "Lower Stormberg Group" of the main Karoo Basin (southern Africa): Implication for the age of the Lower Elliot Formation. Bulletin de la Societe Geologique de France. 175(1), 73-83.

2 comments:

  1. Hi Mickey,
    they look as two shark teeth, perhaps hybodontiform

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  2. Very interesting thought. That would explain why it looks like there are two whorls of three teeth each, given how shark tooth replacement occurs.

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