Astergnathiformes

Astergnathiformes are jawed lagnodactyls, which are distinguished by the presence of a proper circulatory system and vertebrate skeletons.

Family Astergnathidae
Aquatic, fish-like Astergnathiformes which have no vertebrae in front of their pelvic ring, including the most primitive members of the group.

Superfamily Astercranioidea
Astergnathiformes with vertebrae in front of their pelvic ring and a skull derived from said vertebrae.

Family Astercranidae
Aquatic, fish-like Astercranioids.

Family Amphibiasteridae
Amphibious Astercranioids which retain gills in adulthood.

Family Ranasteridae
Amphibious, two-eared Astercranioids which have all of their organs in front of their limb girdle.

Family Cerritulabiidae
Terrestrial, four-eared Astercranioids with long necks, flexible lips, and an arthropod-like abdomen behind their limb girdle.