Lobe-finned fish

Note that osteichthyes is split between actinopterygii, the ray-finned fishes, and sarcopterygii, the lobe-finned fishes.

Actinopterygii includes nearly all of the familiar fish species, like goldfish, mudskippers, eels, seahorses, frogfish, and many others.

Sarcopterygii includes the coelacanths, the lungfish, and tetrapods.

But we will get to those later.

In this tutorial, let's get into the ray-finned fish of class actinopterygii.

And with that, we wrap up the diversity of the ray-finned fishes.

That means it's time to move forward and examine class Sarcopterygii, their sister clade, which includes the lobe-finned fishes and their tetrapod descendants.

Let's move forward and check out this clade now.

Thanks for watching.

But we aren't quite there yet.

For now, that wraps up a summary of the lobe-finned fishes.

Remember that cladistically, all tetrapods are also lobe-finned fishes, but that description doesn't really help much.

In the next tutorial, we will begin to examine the only extant clade of tetrapods that aren't also amniotes, the amphibians, who spread further into the terrestrial environment than the ancient sarcopterygiians.

Thanks for watching.

And-

Tetrapods are all lobe-finned fish.

Sarcopterygians, yes.

[laughs]

Yes, exactly.