Meeting Abstract

LBS3.7  Friday, Jan. 4  Paleontological assessments of diversity dynamics WAGNER, P.J.; Field Museum of Natural History pwagner@fmnh.org

Historically, paleontologists have relied on “synoptic” data sets (i.e., those giving the first and last appearances of fossil taxa) to assess standing richness as well as rates of origination and extinction. However, sampling from the fossil record is inconsistent over time, and there are numerous reasons to suspect that some patterns in sampled richness reflect sampling intensity rather than true differences in relative richness. In recent years, large scale database initiatives have been used to catalog occurrences of taxa and abundances of specimens at particular fossiliferous localities. For example, the Paleobiology Database (PBDB: http://paleodb.org) has nearly 700,000 occurrences from nearly 75,000 localities from throughout the Phanerozoic and across the globe. Accompanying these databases, there has been rapid development of methods that seek to simultaneously estimate sampling, origination and extinction rates among different taxa. An example using PBDB data is presented here, in which rates of diversification among early-mid Paleozoic (latest Cambrian � early Carboniferous) gastropods are contrasted. Here, significant differences can be found between two major clades. However, further examination in a more specific phylogenetic context shows that basic ecologic strategy rather than clade membership is the more likely primary cause of the differences.