Anisopterygia (lit. "unequal flippers") are a clade of Thalattotheria, representing the dominant predators in the ocean.
Since their emergence around 4230ma, Anisopterygians have become apex predators, mostly replacing the Temnopods as the dominant macropredators of the ocean.
Anisopterygians generate most of their speed from their second pair of flippers: the first pair are used to stabilize the cephalothorax, while the hind two pairs are used in steering. At roughly nine meters in length and two meters in height, Anisopterygians are roughly the same size as the Ptilopods.