Thrinacodus is an extinct genus of basal elasmobranch, found worldwide from the Late Devonian-Lower Carboniferous. The type species is Thrinacodus nanus.[1] Most species are only known from their tricuspid teeth. T. gracia, originally placed in the separate genus Thrinacoselache from the Serpukhovian-aged Bear Gulch Limestone, of what is now Montana, is known from full body impressions, showing a long, slender eel-like body up to a metre in length, with an elongate rostrum.[2][3][4] Stomach contents of T. gracia include remains of crustaceans and small chondrichthyan fish (Harpagofututor and Falcatus).[2] It is a member of the Phoebodontiformes.[4]
^ abGrogan, Eileen D.; Lund, Richard (2008). "A basal elasmobranch, Thrinacoselache gracia n. gen and sp., (Thrinacodontidae, new family) from the Bear Gulch Limestone, Serpukhovian of Montana, USA". Journal of Vertebrate Paleontology. 28 (4): 970–988. doi:10.1671/0272-4634-28.4.970. S2CID84735866.
