Njalila

Njalila Temporal range: Late Permian
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Synapsida
Order:	Therapsida
Family:	†Gorgonopsidae
Genus:	†Njalila Gebauer, 2007
Species
†N. nasuta (von Huene, 1950 [originally Dixeya quadrata and Dixeya nasuta]) †N. insigna (Parrington, 1955 [originally Scylacops capensis])

Njalila is an extinct genus of gorgonopsian therapsid from the Late Permian of southern Africa. Fossils have been found from Malawi, Zambia, and Tanzania. Njalila was named in 2007 on the basis of several skulls that had previously been referred to other gorgonopsian genera. Njalila resembles other gorgonopsians in having a deep skull and large caniniform teeth, but it has a uniquely broad, pointed snout.

Description

Njalila has a distinctively short, compact skull. The snout is wide, but the back of the skull is narrower than those of other gorgonopsians. The skull table is slightly concave. Two grooves run along the top of the skull between the eyes and the nostrils. The tip of the snout is sharply pointed, with the nostrils positioned at the very front of the skull. The snout also has bulging septomaxillae beneath the nostrils, but the nasal bones above are very narrow. The temporal fossa, a hole in the skull behind the eye socket, is very large. The borders of fossae form long, thin arches of bone. As in other gorgonopsians, Njalila has large blade-like caniniform teeth. The incisor teeth, however, are smaller than those of related gorgonopsians.^[1]

History

Njalila was erected in 2007 as a replacement name for Dixeya.^[1] Dixeya was first named by German paleontologist Friedrich von Huene in 1950 from Tanzania, Malawi, and Zambia.^[2] The type species of Dixeya, D. quadrata, was reclassified as a species of Aelurognathus in 1970.^[3] Although a second species had been established before the revision, the genus name Dixeya was considered invalid because its type belonged to another genus. The other specie of Dixeya, D. nasuta, was not considered synonymous with Aelurognathus. It was placed in the genus Arctognathus. Moreover, since only the holotype specimen of D. quadrata was assigned to Aelurognathus, other specimens of the species were considered to belong to Arctognathus'.^[3]

The specimens of A. nasuta and A. quadrata possessed many features not seen in other Arctognathus remains. The most notable feature of these specimens was the distinctive pointed snout. When the new genus Njalila was proposed in 2007, two species were erected. A. nasuta was reclassified as N. nasuta, now the type species. A second species, N. insigna, was named on the basis of a skull previously referred to Scylacops. N. insigna has thicker arches between its fossae, a posteriorly wide skull, and a slightly rounded snout profile.^[1]

Njalila was named after the Njalila, a tributary of the Rhuhu River in Tanzania. Most of the skulls belonging to the genus were found near the tributary.^[1]

References

1. ^ ^{a b c d} Gebauer, E.V.I. (2007). Phylogeny and evolution of the Gorgonopsia with a special reference to the skull and skeleton of GPIT/RE/7113 ('Aelurognathus?' parringtoni) (Ph.D. thesis). Tübingen: Eberhard-Karls Universität Tübingen. pp. 1-316. http://tobias-lib.uni-tuebingen.de/volltexte/2007/2935/pdf/Eva_Gebauer.pdf. 
2. ^ Huene, F. von (1950). "Die Theriodontier des ostafrikanischen Ruhuhu-Gebietes in der Tübinger Sammlung". Neues Jahrbuch für Geologie und Paläontologie 92: 47–136. 
3. ^ ^{a b} Sigogneau, D. (1970). "Révision systématique des gorgonopsiens sud-africains". Cahiers de Paléontologie: 1–414. 

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