Waulsortian mudmound

A Waulsortian mudmound is a calcareous formation found in Early Carboniferous strata of Central Europe. It is a type of fossil rich bioconstruction, built by microbial activity in deep tropical waters during the mid-Dinantian. Mud mounds are a high relief, biologically mediated seafloor deposit similar to a reef, but unlike a true reef a mud mound is made almost entirely of uncemented, mud sized matrix grains, and its isolated fossils do not form a supporting skeletal framework.