title: Molecular phylogenetics and historical biogeography amid shifting continents in the cockles and giant clams (Bivalvia: Cardiidae).
abstract: Reconstructing historical biogeography of the marine realm is complicated by indistinct barriers and, over deeper time scales, a dynamic landscape shaped by plate tectonics. Here we present the most extensive examination of model-based historical biogeography among marine invertebrates to date. We conducted the largest phylogenetic and molecular clock analyses to date for the bivalve family Cardiidae (cockles and giant clams) with three unlinked loci for 110 species representing 37 of the 50 genera. Ancestral ranges were reconstructed using the dispersal-extinction-cladogenesis (DEC) method with a time-stratified paleogeographic model wherein dispersal rates varied with shifting tectonics. Results were compared to previous classifications and the extensive paleontological record. Six of the eight prior subfamily groupings were found to be para- or polyphyletic. Cardiidae originated and subsequently diversified in the tropical Indo-Pacific starting in the Late Triassic. Eastern Atlantic species were mainly derived from the tropical Indo-Mediterranean region via the Tethys Sea. In contrast, the western Atlantic fauna was derived from Indo-Pacific clades. Our phylogenetic results demonstrated greater concordance with geography than did previous phylogenies based on morphology. Time-stratifying the DEC reconstruction improved the fit and was highly consistent with paleo-ocean currents and paleogeography. Lastly, combining molecular phylogenetics with a rich and well-documented fossil record allowed us to test the accuracy and precision of biogeographic range reconstructions.
authors.affiliation: Department of Biological Science, Florida State University, Tallahassee, FL 32304, United States. Electronic address: nherrera@bio.fsu.edu.
authors.forename: Nathanael D
authors.initials: ND
authors.lastname: Herrera
authors.affiliation: Naturalis Biodiversity Center, P.O. Box 9517, Leiden, Netherlands; Integrative Research Center, Field Museum of Natural History, Chicago, IL 60605, United States. Electronic address: terpoorten@chello.nl.
authors.forename: Jan Johan
authors.initials: JJ
authors.lastname: Ter Poorten
authors.affiliation: Integrative Research Center, Field Museum of Natural History, Chicago, IL 60605, United States. Electronic address: rbieler@fieldmuseum.org.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Bieler
authors.affiliation: Paleontological Research Institution, and Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14850, United States. Electronic address: pmm37@cornell.edu.
authors.forename: Paula M
authors.initials: PM
authors.lastname: Mikkelsen
authors.affiliation: Smithsonian Institution, National Museum of Natural History, Washington, DC 20013, United States. Electronic address: StrongE@si.edu.
authors.forename: Ellen E
authors.initials: EE
authors.lastname: Strong
authors.affiliation: Department of Geophysical Sciences, University of Chicago, Chicago, IL 60637, United States. Electronic address: djablons@uchicago.edu.
authors.forename: David
authors.initials: D
authors.lastname: Jablonski
authors.affiliation: Department of Biological Science, Florida State University, Tallahassee, FL 32304, United States.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Steppan
mesh_terms: D000818:Animals; D002138:Calibration; D049873:Cardiidae / Q000235:genetics*; D016013:Likelihood Functions; D010802:Phylogeny; D058974:Phylogeography; D013997:Time Factors
keywords: Bayesian; Biodiversity; Dispersal–extinction–cladogenesis; Fossil; Marine; Mollusca