A new limbless vertebrate from the Pennsylvanian of Mazon Creek, Illinois

Abstract

A well preserved aistopod skeleton is descr. Noteworthy features are the extensive fenestration of the skull roof in the temporal region, highly ossified braincase, large orbits with narrow inter orbital septum, forwardly placed jaw articulation, broad epiptery-goid, relatively large otic capsules, large stapedial plate, and differentiated cervical vertebrae. Phlegethontia was probably snake-like in habits rather than fossorial or aquatic. The Aistopoda are regarded as Reptilia rather than Amphibia, and are placed in the Microsauria as a specialized suborder.