Viviparity and intrauterine feeding in a new holocephalan fish from the lower carboniferous of montana.

A new species of Lower Carboniferous holocephalan chondrichthyan, Delphyodontos dacriformes, is described from two fetal specimens. The well-developed slashing and piercing dentition, enlargement of the abdominal region, and fecal material indicate the probable evolution of intrauterine oophagy and viviparity in Paleozoic Chondrichthyes.