Brouffia orientalis (Carroll and Baird 1972) Westphalian, Late Carboniferous, (CGH IIIB 21 c. 587) and counterpart (MP451), specimen 1 of Brough and Brough (1967) was considered very small Gephyrostegus with two sacrals and an intertemporal. Carroll (1970) considered it not congeneric. Carroll and Baird (1972) considered it a primitiive reptile with a single sacral and no intertemporal. Here it nests as a sister to Casineria, as one of the most primitive of all reptiles at the base of the Archosauromorpha. So this specimen provides insight into the configuration of the missing skull of Casineria.
Compared to Gephyrostegus, overall the skull of Brouffia was relatively smaller and relative to the orbit the skull was smaller too. The naris was smaller. The maxilla produced a midlength ascending process. The nasal lost the arrowhead shape and had even, parrallel lateral borders. The jugal was not so deep, rising only to mid orbit. The frontals were likewise parallel laterally, developing posterior extensions. The intertemporal was fused to the parietal. The otic notch was reduced with a straight posterior rim to the posterior squamosal, a key trait of reptiles. The small posterior skull elements bent down. The ventral mandible was slightly convex. No fangs dotted the palate.
The neural spines were lower. More cervicals and more dorsal vertebrae were present. Two sacrals were present.
A slender sternum overlapped the interclavicle ventrally. The cleithrum was more robust. The humerus was a narrow hourglass-shape. The radius and ulna were relatively longer. The manus was more asymmetric than originally reconstructed.
The pelvis was smaller with a proportionately smaller ventral pelvis. The parts were not coosified, but disarticulated. The ilium may have developed an anterior vertical process, an autapomorphy. The proximal tibia was narrower.
Smaller, lighter, longer-waisted, more agile, this basal reptile has a smaller pelvic opening that could only pass relatively smaller eggs. |
