2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 290-2
Presentation Time: 9:00 AM-6:30 PM


KAHANAMOKU, Sara1, HULL, Pincelli1, LINDBERG, David R.2 and FINNEGAN, Seth3, (1)Geology and Geophysics, Yale University, New Haven, CT 06511, (2)Department of Integrative Biology and Museum of Paleontology, University of California, Valley Life Sciences Building, Berkeley, CA 94720-3140, (3)Department of Integrative Biology and Museum of Paleontology, University of California, Berkeley, Valley Life Sciences Building, Berkeley, CA 94720-4780, sara.kahanamoku@gmail.com

For many questions related to body size and shape evolution, a single exemplar measurement is used to represent a species' average state. This approach is taken due to the difficulty and extremely time-intensive nature of measuring size and shape in assemblages using traditional methods, but necessarily ignores intraspecific variation in time and space. Here we showcase a new method, high-throughput imaging, that allows large scale measurement of entire assemblages, collected to reconsider latitudinal gradients in molluscan body size distributions. This type of imaging allows for the conversion of imaged specimens into data that can then be used for morphometric analysis. It is highly useful for projects requiring large numbers of specimens, as a single image can contain hundreds of individuals, and the total image processing time is much less than would be required for manual extraction of size data. Our automated image processing software (Automorph) was designed for use with microfossils; we tested its applicability to macroinvertebrates using recent patellogastropods from the collections of the University of California Museum of Paleontology (UCMP). We focused on the northeastern Pacific coast (Baja California to Alaska), as this region includes strong environmental and climatic gradients and has been subject to intensive study and collecting.