This preliminary study documents both major ecological and morphological changes within the scallop "Pecten" thompsoni from two closely spaced stratigraphic horizons of the Neogene marine sequence of the Dominican Republic. Ecologically, the abundance and dominance of this species differs dramatically between the two samples. Morphometrically, while size does not change significantly, the two populations exhibit statistically different shapes. In addition, there appears to be a shift in ontogenetic patterns where initially an allometric pattern exists but then changes to an isometric growth relationship. These different morphological patterns are consistent with changes in paleoenvironmental conditions. We suggest that a coupled approach of morphometric and paleocommunity analyses may focus future studies on intervals and taxa where evolutionary change may be directly correlated to concomitant ecological changes.
Carol Tang. Department of Invertebrate Zoology and Geology, California Academy of Sciences, 875 Howard Street, San Francisco, California, 94103, USA
Jelena H. Pantel. Department of Invertebrate Zoology and Geology, California Academy of Sciences, 875 Howard Street, San Francisco, California, 94103, USA
currently: Section of Integrative Biology, University of Texas at Austin, 1 University Station C0930, Austin, TX 78712.
Key Words: Dominican Republic, bivalves, evolutionary paleoecology, Neogene
PE Article Number: 8.2.33A
Copyright: Paleontological Society October 2004
Submission: 18 February 2004. Acceptance: 18 April 2005.