Microcosm of the Devonian Microconchids and Cornulitids of Transcaucasia

The data on the first findings of microconchids and cornulitids on the shells of atrypids of Transcaucasia in the range from the Emsian to the Frasnian stage are presented. Epibionts, represented by smooth tubes of the genera Palaeconchus and Cornulites, were found in approximately equal proportions on both the ventral and dorsal flaps of brachiopods. It seems, that the attachment of the studied representatives of the genera Palaeconchus was most likely postmortem, as there is no regularity in their locations. The garlanded nature of the growth of Cornulites, when the constituent members of the garland are approximately of the same size, and the chains of tubes are mouth-directed to the anterior commissure and are located in parallel to the frontal edge, indicates the intravital attachment of these epibionts. During the Devonian period, epibionts were common, though quite rare, elements of the benthic fauna in Transcaucasia. They are characterized by a low level of taxonomic divergence, morphological diversity of adaptive adaptations, and ecological differentiation, which generally indicate the stability of abiotic and biotic environmental conditions.

microconchids, cornulitids, atrypids, epibiontia, Devonian, Transcaucasia