Colosteus scutellatus (Newberry 1856, Hook 1983; Westphalian, Late Carboniferous, 305 mya; 1m in length; AMNH 6916) was originally considered a fish (Pygopterus) and renamed by Cope 1869. Here Colosteus nests between Pholidogaster and Phlegethontia on a branch convergent with traditional tetrapods.
The skull was ovate, the vomers and dentaries had fangs, the fins had transformed to tiny four-fingered limbs. The lacrimal did not reach the external naris. The scales remained large and rhomboid-shaped. Pectoral girdle had not yet evolved an external scapula and coracoid.