Microstructural roughness of skeletal calcite in ophiuroid vertebral ossicles: evidence of wear?
Local areas of roughened skeletal calcite are reported from the otherwise smooth, imperforate skeletal articulations of the ophiuroid vertebral ossicle (Echinodermata: Ophiuroidea). Complementary patterns of roughness on both proximal and distal articulating surfaces suggest local points of wear between adjacent ossicles, presumably caused by repeated rotation of the intervertebral joint. This surface feature is discussed with respect to its possible origin (mechanical action, resorption of skeletal material, experimental artifact) and the functional morphology of the ophiuroid arm skeleton.
LeClair
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Committee on Evolutionary Biology, University of Chicago, Chicago, IL 60637, USA. lecl@midway.uchicago.edu