QUANTIFYING MOLLUSCAN BODY SIZE IN EVOLUTIONARY AND ECOLOGICAL ANALYSES: MAXIMIZING THE RETURN ON DATA-COLLECTION EFFORTS

• DOI: 10.2110/palo.2006.p06-012r
• Publication Date: 2006-12-19T18:48:05Z
• Authors: M. A. KOSNIK; D. JABLONSKI; R. LOCKWOOD; P. M. NOVACK-GOTT...
• Keywords: 0106 biological sciences; 590; 14. Life underwater; 01 natural sciences

How does the choice of size metric, specimen selection, and taxonomic level affect results macroevolutionary or ecological analyses? Four molluscan data sets are used to address this question as follows. First, relationships among various metrics examined using a morphometric set Late Cretaceous–Oligocene veneroid bivalves. Second, relationship between bulk-sampled specimens species' type is bivalves gastropods from Coffee Sand (Upper Cretaceous, Mississippi). Third, same mollusk-dominated field censuses Cincinnatian Ordovician, Ohio, Indiana, Kentucky). Fourth, species genus median literature-derived measurements bivalve recent eastern Pacific continental shelf. Together these provide estimates biases imposed by measuring different kinds methods estimating body size. The geometric mean length height highly correlated with more complex morphometrically based our preferred metric. Bulk randomly sampled significantly smaller than for Cretaceous dataset but larger Ordovician dataset. Genus' type-species an unbiased estimate These suggest that large-scale studies can use proxy type-specimen genus' species, biased bulk specimens. In addition, study emphasizes importance single measurement within suggests combining multiple types (e.g., specimens) could lead substantive errors.