title: Phylogenomic analyses of deep gastropod relationships reject Orthogastropoda.
abstract: Gastropods are a highly diverse clade of molluscs that includes many familiar animals, such as limpets, snails, slugs and sea slugs. It is one of the most abundant groups of animals in the sea and the only molluscan lineage that has successfully colonized land. Yet the relationships among and within its constituent clades have remained in flux for over a century of morphological, anatomical and molecular study. Here, we re-evaluate gastropod phylogenetic relationships by collecting new transcriptome data for 40 species and analysing them in combination with publicly available genomes and transcriptomes. Our datasets include all five main gastropod clades: Patellogastropoda, Vetigastropoda, Neritimorpha, Caenogastropoda and Heterobranchia. We use two different methods to assign orthology, subsample each of these matrices into three increasingly dense subsets, and analyse all six of these supermatrices with two different models of molecular evolution. All 12 analyses yield the same unrooted network connecting the five major gastropod lineages. This reduces deep gastropod phylogeny to three alternative rooting hypotheses. These results reject the prevalent hypothesis of gastropod phylogeny, Orthogastropoda. Our dated tree is congruent with a possible end-Permian recovery of some gastropod clades, namely Caenogastropoda and some Heterobranchia subclades.
authors.affiliation: Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02906, USA felipe_zapata@brown.edu.
authors.forename: Felipe
authors.initials: F
authors.lastname: Zapata
authors.affiliation: Western Australian Museum, Welshpool, WA 6106, Australia.
authors.forename: Nerida G
authors.initials: NG
authors.lastname: Wilson
authors.affiliation: Center for Computation and Visualization, Brown University, Providence, RI 02906, USA.
authors.forename: Mark
authors.identifier: 0000-0002-0764-4090
authors.initials: M
authors.lastname: Howison
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Sónia C S
authors.initials: SC
authors.lastname: Andrade
authors.affiliation: SNSB-Bavarian State Collection of Zoology, Munich 81247, Germany Department Biology II, BioZentrum, Ludwig-Maximilians-Universität, Planegg-Martinsried 82152, Germany.
authors.forename: Katharina M
authors.initials: KM
authors.lastname: Jörger
authors.affiliation: SNSB-Bavarian State Collection of Zoology, Munich 81247, Germany Department Biology II, BioZentrum, Ludwig-Maximilians-Universität, Planegg-Martinsried 82152, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schrödl
authors.affiliation: Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02906, USA.
authors.forename: Freya E
authors.initials: FE
authors.lastname: Goetz
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Giribet
authors.affiliation: Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02906, USA.
authors.forename: Casey W
authors.initials: CW
authors.lastname: Dunn
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D049851:Gastropoda / Q000145:classification* / Q000235:genetics*; D016678:Genome / Q000235:genetics*; D010802:Phylogeny; D017423:Sequence Analysis, RNA; D059467:Transcriptome / Q000235:genetics*
keywords: Gastropoda; Heterobranchia; Mollusca; phylogenomics