Cornulitida is an extinct order of encrusting animals from class Tentaculita, which were common around the globe in the Ordovician to Devonian oceans, and survived until the Carboniferous.

[1][2][3] Organisms that may be the oldest cornulitids have been found in Cambrian sediments of Jordan.

[4] Cornulitids had shells, and were subject to predation by boring and other means from the Ordovician onwards.

[5][6][7] Their affinity is unknown; they have been placed in many phyla, and have been considered worms, corals, molluscs and more.

[1] They appear to be closely related to other taxa of uncertain affinity, including the microconchids, trypanoporids and tentaculitids.