ökologie und Taxonomie koralleninkrustierender Bryozoen des norddeutschen Malm

In the Late Oxfordian Korallenoolith of northern Germany, eight bryozoan taxa encrusting corals have been found, six of which had not been previously recorded in the area. In most cases, they can only be described using open nomenclature since the gonozooids are not known and the type material of existing species is too poorly preserved. “Stationary” bereniciform bryozoans were relatively good competitors adapted to a predictable environment. For this reason they thrived in the calm-water facies. However, the environment was disturbed frequently as proved by the joint occurrence with Stomatoporidae. These “mobile” taxa could grow fast on strongly three-dimensional surfaces, thus being able to survive even in highly agitated facies by escaping into cryptic habitats.

The distribution of individual taxa is thus governed by the type and frequency of perturbations of their habitats. Bryozoans had a binding function in the fauna related to corals. Because of their low number and poor coverage, they mostly had little importance, however. This is due to the high water energy or high rate of sedimentation, which characterized the environments of the sampled localities. Thus, ideal habitats were not available. Nevertheless, the characteristic bryozoan associations of the European Jurassic became established together with typical associated faunal elements.