Constellaria is an extinct genus of bryozoan from the Middle Ordovician to Early Silurian (510-410 million years ago) from North America, Asia and Europe.

These branching coral-like bryozoans formed bushy colonies 10–15 mm (0.375-0.5 inches) across on the seabed.

The fairly thick branches were erect, often compressed in one direction, and covered with distinctive tiny, star-shaped mounds called maculae or monticules (regularly shaped hummocks).

The maculae probably formed "chimneys" for the expulsion of exhalant feeding currents from the surface of a colony, after water had been filtered to obtain food for the organisms.

C. antheloidea (Hall): Late Ordovician, Cincinnati Group, United States of America