undetermined undetermined McDowell 1987

UNGALIOPHIIDAE indet. (Fig. 4 J-N) MATERIAL. — Treznea: one posterior caudal vertebra (UBB V 1048). DESCRIPTION The only available caudal vertebra (UBB V 1048) is known from the Treznea locality (Fig. 4 J-N). It appears well-preserved; however, its surface displays some signs of erosion. The neural arch is strongly depressed and the neural spine is reduced to a low keel. In ventral and lateral views, the centrum possesses a prominent haemal keel, connected to a rounded condyle. The haemal keel is somewhat enlarged posteriorly and displays on the posteroventral side two small knobs (Fig. 4K). REMARKS The main feature of the single available specimen (UBB V 1048) is the presence of a well-developed haemal keel on the subcentral surface, reminiscent of Rieppelophis ermannorum (Schaal & Baszio, 2004), in which the haemapophyses in the caudal vertebrae are replaced by paired knobs (Scanferla et al. 2016: fig. 18B). Additionally, it shares similarities with recent ungaliophiids (Exiliboa and Ungaliophis), which possess a distinct haemal keel in the caudal vertebrae, instead of paired haemapophyses (Szyndlar & Georgalis 2023).