From Ohio History Central
Amphibians, familiar to most people as frogs, toads, and salamanders, first appeared at the end of the Devonian Period. None have been found in Devonian or Mississippian rocks in Ohio, primarily because these rocks are marine. However, Pennsylvanian and Permian rocks have produced many fossil amphibians. Although these remains are very rare in most of these rocks, a few remarkable localities have yielded an abundant and diverse fauna that in many respects has served as the model for life of the coal swamps prevalent at this time.
Most notable is a locality known as Linton, in Jefferson County. Waste rock from a coal mine active in the 1800's, represents sediment deposited in a coal-swamp lake, perhaps an oxbow lake, that teemed with fishes, including paleoniscoids, lungfishes, and freshwater sharks, and many species of amphibians and even early reptiles. At least 22 species of amphibians are known from Linton. Most were small, aquatic forms. One frog-like form, Amphibamus lyelli, probably was primarily terrestrial. A more recently discovered locality in a strip mine in Mahoning County has yielded 13 species of amphibians, most of which are known also from Linton. Pennsylvanian non-marine rocks have yielded occasional footprints and trackways of amphibians.
Permian rocks have produced rare amphibian remains, most of which are poorly preserved. Included in these remains is a large amphibian, Eryops, that was up to three feet long. Specimens of a bizarre amphibian with a bananalike head, Diploceraspis, are known from two localities in southeastern Ohio.
- Hansen, M. C., 1996. "Phylum Chordata--Vertebrate Fossils," in Fossils of Ohio, edited by R. M. Feldmann and Merrianne Hackathorn. Ohio Division of Geological Survey Bulletin 70, p. 288-369.