Belebey vegrandis (Ivakhnenko, 1973)

Reisz, Robert R., Müller, Johannes, Tsuji, Linda & Scott, Diane, 2007, The cranial osteology of Belebey vegrandis (Parareptilia: Bolosauridae), from the Middle Permian of Russia, and its bearing on reptilian evolution, Zoological Journal of the Linnean Society 151 (1), pp. 191-214 : 192

BELEBEY VEGRANDIS IVAKHNENKO, 1973

Holotype: PIN ( Palaeontological Institute , Russian Academy of Science, Moscow, Russia) 104/50 maxillary bone with partly preserved palatine bone.

Referred specimens: SGU (Saratov Geological University, Saratov, Russia) 104/B-2020, a small complete skull that has been disarticulated ( Figs 1–6 ); SGU 104/B-2021, a slightly larger, complete skull ( Figs 7 , 8 ); SGU 104/B-2022, a large, partial skull, preorbital region not preserved. This large individual was available for study but could not be illustrated .

Horizon and locality: Upper Kazanian, Middle Permian; Bashkortostan and Orenburg regions, Southern Russia .

Diagnosis: Bolosaurid parareptiles characterized by the presence of strongly procumbent incisiform dentition anteriorly, and linguo-labially elongated, bulbous, posterior cheek teeth with strongly developed longitudinal striations. Non-dental potential autapomorphies cannot be recognized because most of the other bolosaurid taxa are known from fragmentary cranial and mandibular elements.

Figures

Figure 1. Skull of Belebey vegrandis, SGU 104/B-2020: antorbital region and palate in lateral view, and skull table and temporal region in dorsal view. These are parts of the same skull, prepared and separated from each other. Scale bar = 1 cm; see Appendix 1 for abbreviations list.

Figure 2. Skull of Belebey vegrandis, SGU 104/B-2020: antorbital region of the skull roof and the palate in both dorsal and ventral views. Scale bar = 1 cm; see Appendix 1 for abbreviations list.

Figure 3. Skull of Belebey vegrandis, SGU 104/B-2020: photograph of the antorbital area of the skull in anterior view, showing details of the palate, the medial process of the prefrontal, and the palatine–prefrontal buttress. The dorsal surface of the maxilla, where the largest maxillary teeth are attached, is pockmarked. Scale bar = 1 cm; see Appendix 1 for abbreviations list.

Figure 4. Belebey vegrandis, SGU 104/B-2020: left mandible in medial and lateral views. Scale bar = 1 cm; see Appendix 1 for abbreviations list.

Figure 5. Belebey vegrandis, SGU 104/B-2020: right mandible in medial, lateral and occlusal views. Scale bar = 1 cm; see Appendix 1 for abbreviations list.

Figure 6. Belebey vegrandis, SGU 104/B-2020: photograph of left and right mandibular rami in occlusal view. Scale bar = 1 cm.

Figure 7. Belebey vegrandis, SGU 104/B-2021: skull and mandible in dorsal and lateral views. Scale bar = 1 cm; see Appendix 1 for abbreviations list.

Figure 8. Belebey vegrandis, SGU 104/B-2021: photograph of skull and mandible in palatal view. The skull was not available for illustration in this view. Arrow points to ventral location of the mandibular foramen (mf). Scale bar = 1 cm.