Delphyodontos

Delphyodontos dacriformes is a prehistoric holocephalid fish from the middle Carboniferous-aged Bear Gulch Limestone Lagerstätte, during the Bashkirian Stage in Montana.[1] The adult form is unknown, as the only fossil specimens are of aborted fetuses or recently born young.[2] Sharp teeth and fecal matter in the fossils suggests that Delphyodontos practiced intrauterine cannibalism,[2] like some modern sharks, such as sand tiger sharks.