444-416 million years ago


Ancestral sarcopterygian lineages diverged and the lineage which would evolve into coelacanths separated from that which would lead to lungfish, rhipidistians, and amphibians.

The first coelacanth fossils are known from the middle Devonian. Four genera of sarcopterygians (lungfish and coelacanths) survive today). In 1938, a coelacanth was found off the coast of Madagascar, the first evidence of their existence since the Cretaceous. In coelacanths, the notochord still extends to the pituitary gland and the ratio of brain weight to body weight is similar to that of the most primitive sharks and actinopterygians. Megalocoelocanthus dobiei was a coelacanth from the Cretaceous of the eastern U.S. that could reach 3.5 m in length (Schwimmer, 1994).