Original paper
The taphonomy of Clypeaster: a paleontological tool to identify stable structures in natural shell systems
Grun, Tobias B.; Mancosu, Andrea; Belaústegui, Zain; Nebelsick, James H.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 289 Heft 2 (2018), p. 189 - 202
published: Aug 1, 2018
ArtNo. ESP155028902005, Price: 29.00 €
Abstract
The stability of echinoid skeletons is highly dependent on the strength of the connections between individual elements, such as the plates of the test, which contribute to the construction of these modular organized organisms. Herein, the irregular echinoid genus Clypeaster (Lamarck, 1801) is studied with respect to constructional details of the skeleton, which in turn is of interest as a model for engineered architectural and segmented domes. The preservation of the sea biscuit Clypeaster rosaceus (Linnaeus, 1758) from the Bahamas was studied in detail using micro-CT and scanning electron microscopic methods. Furthermore, field data concerning their preservation is compared to that of Miocene Clypeaster species from the Mediterranean area. The results show that three structural elements affect the test strength: (1) skeletal protrusions interlocking adjoining plates; (2) internal supports crossing plate boundaries and joining the aboral and oral sides of the test; and (3) micro-canals which show a differentiated distribution within the test. The stabilizing features lead to the preservation of denuded complete test on the sea floor for extended periods of time allowing for extensive bioinfestation of the shell. Furthermore, when fragmentation occurs, it preferentially follows the perradial sutures within the ambulacra resulting in typical pie-shaped fragments that are found in both fossil and Recent environments. The potential for using the preservation of shells for biomimetic research is discussed.
Keywords
fragmentation • echinoid • fossil • recent • bahamas • clypeasteroidea • stability • method • test strength • biomimetics