The cranial anatomy of the primitive Carboniferous temnospondyl Cochleosaurus bohemicus is described herein from several large, presumably adult, skulls. This new morphological data modifies earlier descriptions by Frič (=Fritsch in post-1876 publications), Romer and Steen, which were based almost entirely on small, subadult Cochleosaurus bohemicus specimens. Recognition of a new autapomorphy for Cochleosaurus bohemicus, (pitting on the ventral surface of the postorbitals) which is independent of ontogenetic change, has facilitated more accurate intra-specific comparisons between cochleosaurids. Cladistic analysis reveals a clear dichotomy separating the Edopoidea from the more derived clade of the remaining temnospondyls, which includes Balanerpeton and Dendrerpeton. The Edopoidea are only weakly supported as a superfamily in this analysis. The Cochleosauridae are a monophyletic family comprising the genera Procochleosaurus, Adamanterpeton, Cochleosaurus and Chenoprosopus.
