Tetrapodomorpha

Tetrapodomorphs; Fossil range: late Early Devonian - Recent
	; The basal tetrapodomorph Tiktaalik.
Scientific classification
Kingdom:	Animalia;
Phylum:	Chordata;
Subphylum:	Vertebrata;
Class:	Sarcopterygii;
Subclass:	Tetrapodomorpha; Ahlberg, 1991
Subgroups
	See text;

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In Late Devonian vertebrate speciation, descendants of pelagic lobe-finned fish – like Eusthenopteron – exhibited a sequence of adaptations:

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,
- Ichthyostega with limbs.

Descendants also included pelagic lobe-finned fish such as coelacanth species.

Tetrapodomorpha is a clade of vertebrates, consisting of sarcopterygians with a number of features of tetrapods. Primitive forms, like Tiktaalik, have been referred to as "fishapods" by their discoverers, since they were half-fish half-tetrapods, at least in appearance.

Tetrapodomorpha contains the true tetrapods and several groups of related lobe-finned fishes, collectively known as the osteolepiforms.

Among the characters defining the tetrapodomorphs are modifications to the fins, notably a humerus with convex head articulating with the glenoid fossa (the socket of the shoulder joint).

Tetrapodomorph fossils are known from the early Devonian onwards, and include Osteolepis and Panderichthys.