Notes on Fossil Octocorals and Comparisons of Some Modern and Ancient Octocoral Remains

Abstract

Few published reports exist describing fossil octocoral remains, and most deal only with spicules or axial structures. The calcified holdfast has been greatly neglected. Observations of numerous holdfasts indicate features that may possibly be used for identification. Macrostructures such as overall morphology, surface striations or furrows, laminations, a central depression caused by the removal of the axis and an encrusting habit may all be used for gross identification. Microstructures, however, may prove to be much more helpful and may be a key to the identification of fossil holdfasts at the generic level. Study of these microstructures is still in the early stages. The dominant microstrucures are bundles of fibrous aragonite that form hemispheroidal mound-like features separated by thin laminae of gorgonin. The overall texture, size and configuration of the hemispheroids probably are usable for taxonomy, at least to the generic level.