GSA Connects 2021 in Portland, Oregon

Paper No. 106-7
Presentation Time: 3:05 PM


BUCKNER, Janet, Museum of Natural Science, Louisiana State University, 119 Dalrymple Drive, Baton Rouge, LA 70803, ELLINGSON, Ryan, Dept. Ecology and Evolutionary Biology, Univ California - Los Angeles, Los Angeles, CA 90095, GOLD, David, UC DavisEarth and Planetary Sciences, 1 Shields Ave, Davis, CA 95616-5270, JONES, Terry L., Social Sciences, California Polytechnic State University, San Luis Obispo, CA 93407 and JACOBS, David, Dept. Ecology and Evolutionary Biology/Earth, Planetary & Space Sciences, Univ California - Los Angeles, 610 Charles E. Young Dr. East, Los Angeles, CA 90095

Molecular phylogenies have arguably become the most popular framework for inferring clade diversity dynamics. However, data from extinct taxa are notoriously difficult to incorporate and extract with molecular phylogenies. When possible, providing extinct taxa as tips on the phylogeny provides a better understanding of diversification dynamics through time. Furthermore, complete with branch lengths estimated from rates of molecular evolution, the historical character and distribution data from fossils can be directly included in ancestral trait estimation and used in phylogenetic comparative methods to elucidate more complete evolutionary histories for clades. In this study on the extinct anseriforms Chendytes lawi and Camptorhynchus labradorius, we illustrate the added value of incorporating recent extinctions into molecular phylogenies using ancient DNA approaches to understanding clade diversification dynamics. Chendytes lawi, a flightless diving anseriform from coastal California, was traditionally classified as a sea duck, tribe Mergini, based on similarities in osteological characters. We recover and analyze mitochondrial genomes of C. lawi and five additional Mergini species, including Camptorhynchus labradorius. Despite its diving morphology, C. lawi is reconstructed as an ancient relictual lineage basal to the dabbling ducks (tribe Anatini), revealing an additional example of convergent evolution of characters related to feeding behavior among ducks. The Labrador Duck is sister to Steller’s Eider which may provide insights into the evolution and ecology of this poorly known extinct species. We further comment on previous investigations, and our continued study, of the molecular systematics of extinct anserifoms and their implications for understanding evolutionary history in this group.