Romeria? primus (Clark and Carroll 1973) Artinskian, Early Permian, ~280 mya, ~25 mm skull length, was derived from a sister to Concordia and phylogenetically preceded the clades that included Oedaleops, Tetraceratops and Orobates. Romeria? primus nested far from Romeria texana, hence the question mark regarding the generic status of the primus specimen.
Distinct from Concordia, the skull of Romeria? primus had a taller skull, a samller naris and smaller maxillary teeth. The nasals were arrowhead-shaped. The jugal was deeper beneath the orbit. A small indentation began at the posterior skull margin.
The fingers were more gracile.
Olsen (1947) defined the Parareptilia as the most recent common ancestor of millerettids, Acleistorhinus,
Lanthanosuchidae, Macroleter, Procolophonia and all its descendants. According to the present results that common ancestor is Romeria? primus. The name "parareptilia" is inappropriate because the parareptilia should be "beside" the Reptilia, not inside.
DeBraga (2001) defined the Ankyramorpha as the most recent common ancestor of millerettids, Acleistorhinus, Lanthanosuchidae, Macroleter, Procolophonia and all its descendants, but once again, Romeria? primus is that common ancestor, well within the Reptilia.
Such problems arise due a lack of an understanding and a clear picture of the entire reptile family tree brought about by having no overall phylogenetic analysis to start with. Only after such a study is done can smaller studies be carried on with confidence. |
