1 2 3 4 5 6 Caenogastropod mitogenomics 7 David Osca, José Templado, Rafael Zardoya* 8 9 Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, 10 28006, Madrid, Spain 11 Emails:
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[email protected] 12 13 14 15 *Corresponding author 16 17 18 19 Abstract 20 In order to further resolve the phylogenetic relationships within Caenogastropoda, the 21 complete mitochondrial (mt) genomes of Cochlostoma hidalgoi (Cyclophoroidea), 22 Naticarius hebraeus (Naticoidea), Galeodea echinophora (Tonnoidea), and Columbella 23 adansoni (Buccionidea), and the partial mt genome of Erosaria spurca (Cypraeoidea) 24 were sequenced. All newly determined mt genomes conformed to the consensus gene 25 order of caenogastropods, except that of C. hidalgoi, which differed in the relative 26 positions of the trnD, trnQ, trnG, trnY, and trnT genes. Phylogenetic reconstruction of 27 the caenogastropod tree was performed using probabilistic methods and based on the 28 deduced amino acid sequences of concatenated mt protein coding genes. The 29 reconstructed phylogeny recovered Architaenioglossa (superfamilies Cyclophoroidea, 30 Ampullarioidea, and Viviparoidea) as a grade. The monophyly of Sorbeoconcha (all 31 caenogastropods but Architaenioglossa) was supported by most but not all phylogenetic 32 analyses (excluding Vermetoidea, which has a long branch). The relative phylogenetic 33 position of Cerithioidea with respect to Hypsogastropoda remains unresolved. The 34 monophyly of Hypsogastropoda (without Vermetoidea) is strongly supported. Within 35 this clade, Littorinimorpha should be considered a grade. Several superfamilies 36 (Abyssochrysoidea, Rissooidea, Truncatelloidea, and Naticoidea) branched off 37 successively before a siphonate clade (Stromboidea, Cypraeoidea, Tonnoidea, 38 Neogastropoda), which is strongly supported.