EPIBIONT SHADOWING - A HITHERTO UNRECOGNIZED WAY OF PRESERVING SOFT-BODIED FOSSILS

Outlines of soft-bodied sessile epibionts that grew attached to the su rfaces of calcareous shells in ancient seas are sometimes preserved by a process termed 'Epibiont Shadowing'. Processes that altered the sur face of the shell were prevented from happening immediately beneath th e attached epibiont, leaving a shadow of its attachment site following its death and decay. Microboring around the perimeter of the epibiont by presumed endolithic cyanobacteria gave rise to Endolithic Shadows, and dissolution of the calcareous substrate, maybe beneath larger smo thering organisms, produced Solution Shadows of smaller organisms that protected their sites of attachment from such etching effects. Recogn ition of this type of preservation allows the stratigraphic range of c ertain soft-bodied groups to be extended. Details of the shadows may y ield information about the morphological construction of the groups in question.