Ctenacanthus species reported from Kentucky
Maisey (1984) listed known Ctenacanthus species in museum collections and commented on their likely validity, or possible synonyms. Five specimens in his list were originally found in Kentucky, so are included here. All five type specimens are in the American Museum of Natural History collections in New York City. Only one remains a valid species of Ctenacanthus.
- Ctenacanthus angustus was reported from the Subcarboniferous Berea Grit (Late Devonian Berea Sandstone) in Ohio and Lewis County, Kentucky, by Newberry (1889, p. 181). This is surprising because the Berea has few fossils. It remains a valid genus (Maisey, 1981, 1984).
- Ctenacanthus coxianus was reported from the Keokuk Limestone in Missouri and a second specimen is listed from Waverly Series (Upper Devonian Bedford Formation through Mississippian Borden Formation) in Marion County, Kentucky (Eastman, 1902). Maisey (1984) considered it different from Ctenacanthus, but did not assign it to another existing spine genus.
- Ctenacanthus cylindricus was reported by Newberry (1889) from the Keokuk (Borden Formation) in Casey County. Maisey (1984) noted this spine was likely not Ctenacanthus, and might possibly be a Gyracanthus (type of acanthodian fish) spine.
- Ctenacanthus formosus was reported from the Upper Devonian Waverly Series (probably Ohio or Bedford Sh.) in Kentucky, and in the Late Devonian Berea Ss., and Lower Mississippian Cuyahoga Fm., in Ohio by Newberry (1873). It remains a valid species (Maisey, 1984).
- Ctenacanthus furcicarinatus was reported by Newberry (1875, p. 54, Plate 59, Fig. 2). The spine is interesting because it was reported to have been found in association with soft-part leathery skin preservation, a partial tail, and Orodus-like teeth. Orodus teeth are associated with a different type of cartilaginous fish, called the holocephalians. The ornamentation of the fin spine differs from that of a Ctenacanthus, so this specimen is no longer considered a Ctenacanthus spine, although Maisey (1984) did not assign it to another known spine genus.