title: Phylogenomic resolution of scorpions reveals multilevel discordance with morphological phylogenetic signal.
abstract: Scorpions represent an iconic lineage of arthropods, historically renowned for their unique bauplan, ancient fossil record and venom potency. Yet, higher level relationships of scorpions, based exclusively on morphology, remain virtually untested, and no multilocus molecular phylogeny has been deployed heretofore towards assessing the basal tree topology. We applied a phylogenomic assessment to resolve scorpion phylogeny, for the first time, to our knowledge, sampling extensive molecular sequence data from all superfamilies and examining basal relationships with up to 5025 genes. Analyses of supermatrices as well as species tree approaches converged upon a robust basal topology of scorpions that is entirely at odds with traditional systematics and controverts previous understanding of scorpion evolutionary history. All analyses unanimously support a single origin of katoikogenic development, a form of parental investment wherein embryos are nurtured by direct connections to the parent's digestive system. Based on the phylogeny obtained herein, we propose the following systematic emendations: Caraboctonidae is transferred to Chactoidea new superfamilial assignment: ; superfamily Bothriuroidea revalidated: is resurrected and Bothriuridae transferred therein; and Chaerilida and Pseudochactida are synonymized with Buthida new parvordinal synonymies: .
authors.affiliation: Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA psharma@amnh.org.
authors.forename: Prashant P
authors.initials: PP
authors.lastname: Sharma
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
authors.forename: Rosa
authors.initials: R
authors.lastname: Fernández
authors.affiliation: Essig Museum of Entomology, University of California at Berkeley, 130 Mulford Hall, Berkeley, CA 94720, USA.
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Esposito
authors.affiliation: Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigaciones y de Estudios Avanzados del Instituto Politecnico Nacional, and Laboratorio de Aracnología, Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Coyoacán, C.P. 04510, México DF, México.
authors.forename: Edmundo
authors.initials: E
authors.lastname: González-Santillán
authors.affiliation: Département des Arthropodes et d'Entomologie I, Muséum d'Histoire Naturelle de la Ville de Genève, Route de Malagnou 1, Genève 1208, Switzerland.
authors.forename: Lionel
authors.initials: L
authors.lastname: Monod
mesh_terms: D000818:Animals; D005075:Biological Evolution; D019143:Evolution, Molecular; D016678:Genome; D008969:Molecular Sequence Data; D010802:Phylogeny; D012605:Scorpions / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics*; D017422:Sequence Analysis, DNA
keywords: Arthropoda; arachnids; missing data; paralogy; relict; transcriptomics