Biology:Njalila

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Short description: Extinct genus of therapsids

Njalila
Temporal range: Late Permian
Scientific classification e
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Synapsida
Clade: Therapsida
Clade: Gorgonopsia
Family: Gorgonopsidae
Genus: Njalila
Gebauer, 2007
Species
  • N. nasuta (von Huene, 1950 [originally Dixeya nasuta]) (type)
  • "N. insigna" Gebauer, 2007

Njalila is an informal name for a genus of gorgonopsian therapsids from the Late Permian of southern Africa. Fossils have been found from Malawi, Zambia, and Tanzania.

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

The type species of "Njalila", N. nasuta, was originally assigned to Dixeya, which was 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 species 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]

However, "Dixeya" nasuta possesses many features not seen in other Arctognathus remains. The most notable feature of these specimens was the distinctive pointed snout. A second species, "N. insigna", is based on a skull previously referred to Scylacops capensis. "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]

Classification

Placement of Njalila within the taxon Gorgonopsia according to Gebauer (2007):[1]

Gorgonopsia 

Aloposaurus

Cyonosaurus

Aelurosaurus

Gorgonopsidae

Scylacognathus

Eoarctops

Gorgonops

Njalila

Lycaenops

Arctognathus

Inostrancevia

Rubidgeinae

Aelurognathus

Rubidgea

Sycosaurus

Clelandina

References

  1. 1.0 1.1 1.2 1.3 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) (PDF) (Ph.D. thesis). Tübingen: Eberhard-Karls Universität Tübingen. pp. 1–316.
  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. 3.0 3.1 Sigogneau, D. (1970). "Révision systématique des gorgonopsiens sud-africains". Cahiers de Paléontologie: 1–414. 


Wikidata ☰ Q7042385 entry