Youngoides romeri FMNH UC1528 (Olson and Broom 1937) Late Permian ~255 mya was derived from a sister to Youngina AMNH 5561 and precededEuparkeria at the base of the Eurchosauriformes.
Distinct from AMNH 5561, the skull of UC1528 had smaller temporal fenestrae and more robust bones surrounding it. The squamosal and quadrate were vertical. The frontal has no posterior processes. The teeth are small, narrrow and recurved. The pineal foramen is tiny. The premaxilla is short producing anteriorly oriented nares. Note the slit-like beginning of the antorbital fenestra at the juncture of the jugal, lacrimal and maxilla (see below). The bone is worn away on the maxilla, exposiing the lacrimal extending to the naris. The right angle occiput overlies the larger squamosal below it. On succeeding taxa the squamosal retreats toward the top. |
