Functional morphology and paleoecology of some sessile Middle Cambrian echinoderms from the Barrandian region of Bohemia


Authors: Parsley RL, Prokop RJ

Published in: Bulletin of Geosciences, volume 79, issue 3; pages: 147 - 156; Received 21 February 2003; Accepted in revised form 21 May 2004;

Keywords: Cambrian, eocrinoids, edrioasteroids, biogluing, “snowshoeing”, mixed layer,

full text (PDF, 0.61 MB)

Export to RIS



Sessile Early and Middle Cambrian edrioasteroids and eocrinoids probably attached by biologically derived glue to siliciclastic sea bottoms, which were slightly to not at all bioturbated. The most likely glue available in echinoderms is mutable extensible collagen tissue (MCT). Holdfasts on the eocrinoid Lichenoides and the edrioasteroid Stromatocystites are made up of small platelets that could have extruded collagen along and out from the platelet sutures. A new species Lichenoides vadosus sp. n. is especially adapted for shallow water, high energy environments, and Stromatocystites flexibilis sp. n. is well adapted for deep, quiet water conditions. Thecal and holdfast morphology reflects these conditions. Both species are described here. Other Lower and Middle Cambrian echinoderms were recumbent on the seafloor and have flattened thecae and commonly an elongated appendage for locomotion and orientation. Some of these forms were well adapted to a non-bioturbated sea floor and did not adjust to the development of the mixed layer (homosteles and ctenocystoids), though stylophorans, homoiosteles, rhipidistian eocrinoids, and pleurocystioids did.