CRANIAL OSTEOLOGY AND A NEW DIAGNOSIS OF THE LATE PERMIAN PAREIASAUR NANOPARIA LUCKHOFFI (BROOM, 1936) FROM THE KAROO BASIN OF SOUTH AFRICA, AND A CONSOLIDATED PAREIASAURIAN PHYLOGENY

VAN DEN BRANDT M.; CISNEROS, J. C.; ABDALA, F.; BOYARINOVA, E. I.; GOLUBEV, V. K.; GOLUBEV, V.

REVISTA BRASILEIRA DE PALEONTOLOGIA

SOC BRASILEIRA PALEONTOLOGIA

Año: 2024 vol. 26 p. 288 - 314

1519-7530

Pareiasaurs were an enigmatic and diverse group of parareptilian herbivores of the middle and late Permian. Nanoparia luckhoffi was erected in 1936 but remains the least well-known member of four “dwarf” pareiasaurs that comprise Pumiliopareiasauria. After new preparation of the holotype, we present the first detailed cranial description of Nanoparia luckhoffi and a new diagnosis for the taxon based on seven autapomorphies: (1) an additional bone on the posterior margin of the cheek flange between the squamosal and quadratojugal; (2) a pyramidal-shaped parietal; (3) a very short, square lacrimal; (4) paired prepalatal foramina positioned anterolaterally on the internalpremaxillary palatal flange; (5) notch on anteromedial border of the choana; (6) a ventral flange formed by the lateral margin of the internal tabulars; and (7) tabulars that extend posteriorly further than the supratemporals. We find evidence supporting a juvenile ontogenetic state for the holotype, including small skull; unossified open cranial sutures; an unossified dorsal braincase; and fewer marginal teeth than most pareiasaurs. An updated phylogeny recovers Nanoparia as a sister taxon to Provelosaurus americanus from Brazil and remains a constituent member of Pumiliopareiasauria.