Bryozoans (or Ectoprocta) are a phylum of tiny organisms that have lived abundantly from the ancient geological past up to this day, forming large colonies in an aquatic environment, preferably warm. They are often referred to as mossy organisms, but. they have calcitic skeletons of a more or less dendritic makeup with which they can form mats over large surfaces. The specimen here seen is found in moraine deposits accumulated during the Pleistocene Ice Ages in the north Netherlands. Such boulders and debris in these deposits are mostly derived from rocks of the Paleozoic era in Scandinavia. Actual width of sample is 150 mm.