See more from this Division: Topical Sessions
See more from this Session: Phylogenetic Perspectives on Assembling the Tree of Life in Deep Time
Abstract:
The differential evolution among the elements in a single apparatus provides a natural experiment in cladistic systematics. Synapomorphies in the P2 elements can be used to characterize derived genera from a conservative family-level stock recognized by similar S elements, and sequential apomorphic P1 elements show different species evolving within a genus. What these relationships demonstrate is that conodont clades often evolved iteratively from relatively conservative stock, with individual genus-level clades radiating to fill particular niches. Because P1 elements commonly evolved through heterochrony, a major complication for conodont biostratigraphy is homeomorphy. Reincorporating the entire apparatus into conodont taxonomy helps resolve these problems. Examples from the Late Paleozoic are presented to illustrate the utility of this systematic approach and to reconstruct otherwise difficult to understand phylogenetic relationships. The next step is to apply these methods to recognize paleobiogeographic variation around Pangea, where traditional form taxonomy, based solely on P1 element morphology, has failed to produce reliable biostratigraphic results.
See more from this Division: Topical Sessions
See more from this Session: Phylogenetic Perspectives on Assembling the Tree of Life in Deep Time