Leptocretidae

Leptocretidae is a family of bryozoans, a group of small, colonial animals that are attached to underwater surfaces. They belong to the class Stenolaemata, which also includes phylloid algae and other types of stenolaemate bryozoans. Leptocretid bryozoans are distinguished by their unique body form, which features a craze of autozooidal zooids, each with a short, shrubby colony.

These bryozoans are found in marine environments around the world, typically in areas with calm water and coarse sediment. They have been fossilized and preserved in rocks dating back to the Early Ordovician period, over 450 million years ago. Analysis of their fossil record has helped paleontologists make inferences about ancient ocean currents, tectonic activity, and other geological processes.

The most distinctive feature of Leptocretidae is the non-homoplastic irregularity of their zooids, which contrasts with the regular cribrid-like shape of other stenolaemate bryozoans. The mouth of a Leptocretidae's linear monoporal, which surrounds the colony, is an opening through which water enters. After flowing through the colony, the water exits from an external opening.

The zooids of Leptocretid bryozoans have a " creeping" characteristic due to their unicolumellate calcareous zooecia preservation. This creeping appearance aids the crawling-like behavior of Leptocretid growth.