Otavia antiqua is an early sponge-like fossil found in Namibia in the Etosha National Park.

It is claimed to be the oldest animal fossil, being found in rock aged between 760 and 550 million years ago.

The genus was named after the Otavi Group in Namibia in which the fossils were found.

They are hollow inside, and have many small, osculum-like holes connecting the interior to the outside.

[1] The affinities of these fossils, along with other paleontological evidence for precambrian sponges, are disputed.