Cherninia megarhina ( Chernin & Cosgriff, 1975 ) Damiani, 2001

Steyer, Jean-Sébastien, Peecook, Brandon R., Arbez, Thomas, Nesbitt, Sterling J., Tolan, Steve, Stocker, Michelle R., Smith, Roger M. H., Angielczyk, Kenneth D. & Sidor, Christian A., 2021, New data on the Triassic temnospondyls from the Karoo rift basins of Tanzania and Zambia, Geodiversitas 43 (12), pp. 365-376 : 372-373

cf. Cherninia megarhina ( Chernin & Cosgriff, 1975) Damiani, 2001

( Fig. 7 )

REFERRED MATERIAL. — Zambia. NHCC LB676, a partial but elongate left dentary of an adult individual based on its well-developed ornamentation (e.g., Steyer 2000). It was found by one of us (ST) in 2007, associated with many specimens of the bivalve Unio karooensis Cox, 1932 .

LOCALITY AND HORIZON. — Locality L66 near the village of Sitwe, upper horizon of the Ntawere Formation, Middle-?Late Triassic (e.g., Battail 1993; Hancox 2000; Peecook et al. 2018) of the Luangwa Basin (sensu Barbolini et al. 2016).

DESCRIPTION

This partial dentary corresponds to the anterior half of the element. Its face is weathered with many broken teeth alongside their sockets, but it is not deformed by compaction. Its bears at least 50 laterally compressed teeth or tooth sockets. In lingual view ( Fig. 7A ), the dentary is elongate (L = 380 mm) and naturally shallow (h = 61 mm max). In dorsal view ( Fig. 7B ), its anterior extremity is strongly curved and semi-circular, with a well-developed symphyseal region. The symphyseal region bears two large partial tusks and is expanded posteriorly, with an elongate symphyseal suture (59 mm).

IDENTIFICATION

Laterally compressed teeth are a stereospondyl synapomorphy (e.g., Yates & Warren 2000), whereas an elongate symphyseal suture is a common feature in Mastodonsauridae (e.g., Damiani 2001b). The semi-circular curvature of the dentary in dorsal view, together with its very large size, suggests a possible attribution of this specimen to Cherninia megarhina . This taxon is characterized by a very large skull and a semi-circular snout ( Chernin 1974; Damiani 2001a), and the proportions and shape match those of NHCC LB676. Moreover, the type material of C. megarhina (BP/1/4223, a partial skull) was collected in the same region from time-equivalent strata (the type locality is “Locality 15” of Drysdall & Kitching 1963, also near the village of Sitwe). However, because the mandible of C. megarhina described by Chernin (1978) does not belong to the type material, we cautiously assign NHCC LB676 to “cf. Cherninia megarhina ”.

Figures

FIG. 7. — Partial left dentary of cf. Cherninia megarhina (Chernin & Cosgriff,1975) (NHCC LB676) from the Triassic (?Anisian) of Zambia (Luangwa Basin) in lingual (A) and dorsal (B) views. Abbreviations: d, dentary; sym, symphyseal suture. Scale bar: 10 cm.