The former never left the oceans and their heyday was the late Devonian and Carboniferous , from 385 to 299 Ma , as they were more common during those periods than in any other period in the Phanerozoic ; coelacanths still live today in the oceans ( genus `` Latimeria '' ) .
The former never left the oceans and their heyday was the late Devonian and Carboniferous , from 385 to 299 mya , as they were more common during those periods than in any other period in the Phanerozoic ; coelacanths still live today in the oceans ( genus `` Latimeria '' ) .