Original paper
Njalila gen. nov. (Therapsida. Gorgonopsia): a new genus for Dixeya nasuta v. Huene, 1950 from the Late Permian Usili Formation of the Ruhuhu Basin, SW Tanzania
Gebauer, Eva V. I.; Maisch, Michael W.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen (2026)
59 references
published online: Jan 8, 2026
manuscript accepted: Dec 3, 2025
manuscript received: May 31, 2025
DOI: 10.1127/njgpa/1296
Abstract
The gorgonopsian genus Njalila gen. nov. (Therapsida, Gorgonopsia) from the Late Permian Usili Formation of the Ruhuhu Basin in southwestern Tanzania is erected for the reception of the species Dixeya nasuta v. Huene, 1950. Njalila is diagnosed on the basis of multiple cranial features, including several autapomorphies, such as the tip of snout pointing dorsally, the septomaxilla bulged anteriorly while forming the lateral margin of the external naris, the dorsal skull roof deeply concave between the orbits with prefrontal short and situated on a marked elevation, and the palate with a ‘pre-fossa’ anterior to the fossa between the palatal tuberosities. A review of the research history on the specimens attributable to Njalila and a discussion on their status is provided, as is a discussion of the status of the original type species of Dixeya, D. quadrata Haughton, 1927. It is concluded that D. quadrata is not congeneric with D. nasuta. It can presently only be considered Gorgonopsia incertae sedis, but may have closer relationships to the genus Lycaenops than envisaged by previous authors. All the remaining ‘Dixeya’-material, currently identified as Arctognathus? nasuta and cf. Arctognathus? nasuta, from the Usili Formation of Tanzania, is attributed to a single species, Njalila nasuta. A single specimen, originally described as a representative of the South African taxon Scylacops capensis, shows some morphological divergence from the remaining specimens, but clearly represents Njalila. It is cautiously determined as Njalila cf. nasuta. Njalila and Arctognathus are compared in detail, and differences that suggest generic separation are recorded. Phylogenetic analysis shows Njalila to be a moderately derived member of the ‘African clade’ of gorgonopsians. A potential sister-group relationship to Arctognathus is indicated, but weakly supported by the currently available data. urn:lsid:zoobank.org:pub:F4103A77-078E-4F14-87F4-95D76791D5B3
Keywords
Gorgonopsia • Late Permian • Ruhuhu Basin • Tanzania • Usili Formation • morphology • taxonomy • phylogeny