Nimbia occlusa is a form of Ediacaran fossil shaped like a circular or oval disk, with a thick rim around the margin.

These fossils were generally believed to be those of cnidarians, but they have since been reinterpreted as structures made by microbial colonies (Grazhdankin, see Ediacaran biota for references and discussion).

Nimbia occurs in numerous locations across a large range of time, which lends weight to theories that the fossil does not represent a single animal species.

It occurs in the Twitya Formation in the Mackenzie Mountains in Canada dated at 610 million years ago, near the end of the Marinoan glaciation, and in 770 million years ago rocks in Kazakhstan.

Morania and Beltina carbonaceous film fossils in the Twitya Formation are not considered to be animals.