Other animals that would later be classified as temnospondyls were placed in a group called Ganocephala , characterized by plate @-@ like skull bones , small limbs , fish @-@ like scales , and branchial arches . Unlike labyrinthodonts , they did not have parietal foramena , small holes in their skulls behind their eye sockets . Archegosaurus , Dendrerpeton , Eryops and Trimerorhachis were placed in this group and were considered to be the most primitive members of Reptilia . Their rhachitomous vertebrae , notochord , and lack of occipital condyles ( which attached the head to the neck ) were features that were also shared with fishes . Thus , they were considered a link between early fishes and more advanced forms such as stegocephalians .