The late Paleozoic “redbeds” vertebrate fauna, best known from the deposits in the Wichita region of north central Texas, was considered by its discoverer, Cope, to be of Permian nature, and this belief is still held by many writers. Case, in 1908, announced the discovery of reptilian remains in red sediments of Pennsylvania age, and rightly concluded that the redbeds fauna was to be regarded as Permo-Carboniferous, pertaining to both systems. Nevertheless, the fauna is still treated generally as typically Permian, and, in particular, the Texas beds containing the major part of known finds have been universally assumed to be entirely of Permian age.
It was early seen that some difference existed between the vertebrate assemblages in the lower and those in the upper portions of the Texas deposits included in the Wichita and Clear Fork groups. In 19281 the writer, following an investigation of the vertical distribution of . . .