title: Restructuring higher taxonomy using broad-scale phylogenomics: The living Ophiuroidea.
abstract: The power and throughput of next-generation sequencing is instigating a major transformation in our understanding of evolution and classification of life on our planet. The new trees of life are robust and comprehensive. Here we provide a landmark phylogeny of the living ophiuroids and use it as the basis for a major revision of the higher classification of this class of marine invertebrates. We used an exon-capture system to generate a 1484 exon (273kbp) data-matrix from DNA extracted from ethanol-preserved museum samples. We successfully obtained an average of 90% of our target sequence from 576 species spread across the known taxonomic diversity. The topology of the major lineages was robust to taxon sampling, exon-sampling, models and methods. However, estimates of node age were much less precise, varying by about a quarter of mean age. We used a combination of phylogenetic distinctiveness and temporal-banding to guide our revision of the family-level classification. Empirically, we determined that limiting family crown age to 110±10Ma (mid Cretaceous) selected phylogenetically distinct nodes while minimising disruption to the existing taxonomy. The resulting scheme of 32 families and six orders considerably expands the number of higher taxa. The families are generally longitudinally widespread across the world's oceans, although 17 are largely confined to temperate and equatorial latitudes and six to relatively shallow water (less than 1000m depth).
authors.affiliation: Marine Invertebrates, Sciences, Museum Victoria, GPO Box 666, Melbourne, Victoria 3000, Australia. Electronic address: tohara@museum.vic.gov.au.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: O'Hara
authors.affiliation: Marine Invertebrates, Sciences, Museum Victoria, GPO Box 666, Melbourne, Victoria 3000, Australia. Electronic address: ahugall@museum.vic.gov.au.
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Hugall
authors.affiliation: Section Paléontologie, Musée National d'Histoire Naturelle du Luxembourg, 24 Rue Münster, 2160, Luxembourg.
authors.forename: Ben
authors.initials: B
authors.lastname: Thuy
authors.affiliation: Swedish Museum of Natural History, Department of Zoology, Box 50007, 104 05 Stockholm, Sweden.
authors.forename: Sabine
authors.initials: S
authors.lastname: Stöhr
authors.affiliation: Zoological Museum, Moscow State University, Bolshaya Nikitskaya Str. 6, Moscow 125009, Russia.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Martynov
mesh_terms: D000818:Animals; D030541:Databases, Genetic; D004447:Echinodermata / Q000145:classification* / Q000235:genetics*; D005091:Exons / Q000235:genetics; D023281:Genomics; D010802:Phylogeny; D059467:Transcriptome / Q000235:genetics
keywords: Deep sea; Exon capture; Invertebrates; Marine; Ophiuroidea; Phylogenomics; Temporal-banding