A cochleosaurid temnospondyl amphibian from the Middle Pennsylvanian of Linton, Ohio, U.S.A.

Two temnospondyl amphibian specimens from the Middle Pennsylvanian locality of Linton, Ohio, USA are described as Adatnanterpeton ohioensis gen. et sp. nov. , a member of the family Cochleosauridae and sister-taxon to the clade comprising the genera Cochleosaurus+Chenoprosopus. A. ohioensis is a very rare component in the large Linton vertebrate assemblage and may have been a relatively terrestrial form, perhaps similar to Cochleosaurus florensis from the contemporaneous lycopsid-trunk locality at Florence, Nova Scotia. An overview of the edopoid and eryopoid adaptive radiations is presented and it is argued that they were sequential radiations, each of monophyletic origin filling the same range of niches.