title: A family-level Tree of Life for bivalves based on a Sanger-sequencing approach.
abstract: The systematics of the molluscan class Bivalvia are explored using a 5-gene Sanger-based approach including the largest taxon sampling to date, encompassing 219 ingroup species spanning 93 (or 82%) of the 113 currently accepted bivalve families. This study was designed to populate the bivalve Tree of Life at the family level and to place many genera into a clear phylogenetic context, but also pointing to several major clades where taxonomic work is sorely needed. Despite not recovering monophyly of Bivalvia or Protobranchia-as in most previous Sanger-based approaches to bivalve phylogeny-our study provides increased resolution in many higher-level clades, and supports the monophyly of Autobranchia, Pteriomorphia, Heteroconchia, Palaeoheterodonta, Heterodonta, Archiheterodonta, Euheterodonta, Anomalodesmata, Imparidentia, and Neoheterodontei, in addition to many other lower clades. However, deep nodes within some of these clades, especially Pteriomorphia and Imparidentia, could not be resolved with confidence. In addition, many families are not supported, and several are supported as non-monophyletic, including Malletiidae, Nuculanidae, Yoldiidae, Malleidae, Pteriidae, Arcidae, Propeamussiidae, Iridinidae, Carditidae, Myochamidae, Lyonsiidae, Pandoridae, Montacutidae, Galeommatidae, Tellinidae, Semelidae, Psammobiidae, Donacidae, Mactridae, and Cyrenidae; Veneridae is paraphyletic with respect to Chamidae, although this result appears to be an artifact. The denser sampling however allowed testing specific placement of species, showing, for example, that the unusual Australian Plebidonax deltoides is not a member of Donacidae and instead nests within Psammobiidae, suggesting that major revision of Tellinoidea may be required. We also showed that Cleidothaerus is sister group to the cementing member of Myochamidae, suggesting that Cleidothaeridae may not be a valid family and that cementation in Cleidothaerus and Myochama may have had a single origin. These results highlight the need for an integrative approach including as many genera as possible, and that the monophyly and relationships of many families require detailed reassessment. NGS approaches may be able to resolve the most recalcitrant nodes in the near future.
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Combosch
authors.affiliation: Department of Biological Sciences, Florida International University, Miami, FL 33199, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Collins
authors.affiliation: Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK.
authors.forename: Emily A
authors.initials: EA
authors.lastname: Glover
authors.affiliation: Biology Department, University of Wisconsin-Stevens Point, 800 Reserve Street, Stevens Point, Wisconsin 54481, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Graf
authors.affiliation: Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Harper
authors.affiliation: Queensland Museum, PO Box 3300, South Brisbane, Queensland 4101, Australia.
authors.forename: John M
authors.initials: JM
authors.lastname: Healy
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA; Zoology Department, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Gisele Y
authors.initials: GY
authors.lastname: Kawauchi
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Lemer
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: McIntyre
authors.affiliation: Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, PO Box 37012, MRC 163, Washington, DC 20013, USA.
authors.forename: Ellen E
authors.initials: EE
authors.lastname: Strong
authors.affiliation: Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK.
authors.forename: John D
authors.initials: JD
authors.lastname: Taylor
authors.affiliation: Department of Biology, The Citadel, 171 Moultrie Street, Charleston, SC 29409, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Zardus
authors.affiliation: Integrative Research Center, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605, USA.
authors.forename: Paula M
authors.initials: PM
authors.lastname: Mikkelsen
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA; Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK; Integrative Research Center, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605, USA. Electronic address: ggiribet@g.harvard.edu.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Giribet
authors.affiliation: Integrative Research Center, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605, USA.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Bieler
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D049872:Bivalvia / Q000145:classification* / Q000235:genetics*; D016013:Likelihood Functions; D010802:Phylogeny; D017422:Sequence Analysis, DNA / Q000379:methods*
keywords: Bivalvia; Mollusca; Phylogenetics; Protobranchia; Pteriomorphia; Sanger sequencing