''Macroscelesaurus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

therocephalian Therocephalia is an extinct suborder of eutheriodont therapsids (mammals and their close relatives) from the Permian and Triassic. The therocephalians ("beast-heads") are named after their large skulls, which, along with the structure of their t ...

therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

from the

Late Permian Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

''Macroscelesaurus janseni'' was named by

Sidney H. Haughton Sidney Henry Haughton FRS (7 May 1888 – 24 May 1982) was an English-born South African paleontologist and geologist best known for his description of the sauropodomorph dinosaur '' Melanorosaurus'' in 1924, and his work on the geology of ...

in 1918 from the ''Cistecephalus'' Assemblage Zone. It is one of the few therocephalians known from postcranial remains.

Description and history

''Macroscelesaurus'' is known from a single

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

consisting of the

mold A mold () or mould () is one of the structures certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi. Not ...

of a partial skeleton. The impression was found on a sandstone block that made up the wall of a kraal or sheep enclosure near the town of

Victoria West Victoria West is a town in the central Karoo region of South Africa's Northern Cape province. It is situated on the main N12 route, at an elevation of . It is the seat of the Ubuntu Local Municipality within the Pixley ka Seme District Municipa ...

. It includes most of the postcranial skeleton, including the vertebral column, ribs, limbs, and the pelvic and pectoral girdles. Most of the skull is not preserved. The skeleton is preserved in ventral view, with the body curving to the right and the limbs bent to one side. The specimen was brought to South African paleontologist Sidney H. Haughton, and formally described the next year. On the basis of the impression, Haughton designated the species ''Macroscelesaurus janseni'', after the discoverer of the specimen, F. J. Jansen. Although it was not found in a deposit, Haughton thought that the specimen originated from rock layers belonging to the ''Tapinocephalus'' Assemblage Zone. The fossil is now thought to have been from the younger ''Cistecephalus'' Assemblage Zone. German paleontologist

Oskar Kuhn Oskar Kuhn (7 March 1908, Munich – 1990) was a German palaeontologist. Life and career Kuhn was educated in Dinkelsbühl and Bamberg and then studied natural science, specialising in geology and paleontology, at the University of Munich, f ...

renamed ''Macroscelesaurus'' as ''Haughtoniscus'' in 1934, as he thought the original name was too similar to '' Macroscelosaurus'', the generic name for a prolacertiform reptile that had described in 1852. Under the rules of the

International Code of Zoological Nomenclature The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the ...

, Kuhn's renaming was inappropriate and the name ''Macroscelesaurus'' is still considered valid.

Classification

Haughton considered placing it within

Dromasauria Dromasaurs are a paraphyletic group of anomodont therapsids from the Middle Permian. They were small with slender legs and long tails. Their skulls were short, but the eye sockets were large. Dromasauria was once considered to be a major group of ...

, a group of small anomodont therapsids. Most similarities between the two therapsids were seen in the limbs. He noted several differences, including the relatively large hind limbs of ''Macroscelesaurus'' (the fore and hind limbs of dromasaurians are about equal in length) and enlarged canines, which are not seen in dromasaurians. Haughton also considered the possibility that ''Macroscelesaurus'' was a

therocephalia Therocephalia is an extinct suborder of eutheriodont therapsids (mammals and their close relatives) from the Permian and Triassic. The therocephalians ("beast-heads") are named after their large skulls, which, along with the structure of their ...

n therapsid, because it shared more features in common with '' Ictidosuchus'' than any other therapsid. ''Macroscelesaurus'' is now classified in the therocephalian clade Baurioidea, although its exact position is uncertain.

References

{{Taxonbar, from=Q6725619 Lopingian synapsids of Africa Baurioids Lopingian genus first appearances Lopingian genus extinctions