In the later Devonian, descendants of pelagic lobe-finned fish — like Eusthenopteron — were followed by: Panderichthys, suited to muddy shallows; Tiktaalik with limb-like fins that could take it onto land; Early tetrapods in weed-filled swamps, such as: Acanthostega, which had feet with eight digits, and Ichthyostega with limbs. Descendants also included pelagic lobe-finned fish such as coelacanth species.
Coelacanths are the only living sarcopterygians that live in the ocean
The Sarcopterygii is a class of fish. They are lobe-finned fish, like the lungfish and coelacanths. They are a clade of bony fish which first appeared in the Silurian, 418 million years ago (mya). One line in this group gave rise to the tetrapods.