Evolutionary relationships among the Pulmonate land snails and slugs (Pulmonata, Stylommatophora)

Abstract

We have incorporated an additional 56 species of land snails and slugs in our ribosomal (r) RNA molecular phylogeny. The new taxa include representatives of several important groups. The molecular tree now includes 160 species of stylommatophoran land snails and slugs in 144 genera in 61 families. In the rDNA tree, the Stylommatophora are principally divided into an 'achatinoid' and a 'non-achatinoid' clade. Within these clades, several major land snail groups, including the Orthurethra, Elasmognatha, Limacoidea, and Helicoidea, are supported. Overall, the rDNA molecular phylogeny has remained stable following the incorporation of the additional taxa, with these additions having little impact on the major evolutionary patterns in the tree. Taxonomic coverage of the Orthurethra, Orthalicidae, Camaenidae, and Bradybaenidae is increased significantly. The camaenids and bradybaenids form a complex, and both appear to be paraphyletic. Several families of uncertain affinity, such as the Sagdidae and Thyrophorellidae, are included for the first time. The Sagdidae are shown to belong to the Helicoidea, and the Thyrophorellidae to the Achatinoidea.

The development and evolution of left‐right asymmetry in invertebrates: Lessons from Drosophila and snails

“…6) has been confirmed in four families of pulmonates (Boycott et al, 1930;Degner, 1952;Murray and Clarke, 1976;Ueshima and Asami, 2003;Asami et al, 2008) that are phylogenetically independent (Wade et al, 2006). Although polarity determination by a maternal effect is, therefore, likely to be general, at least in pulmonates, it has not been verified in other groups of gastropods.…”

“…Snails are, however, unique in having repeatedly achieved chiral speciation, in which whole-body enantiomorphs have evolved as separate species. Furthermore, the enantiomorphs of primary asymmetry coexist within populations of a number of species in the tree-snail genera Achatinella, Amphidromus, and Partula, which are phylogenetically independent of each other (Wade et al, 2006). Especially in Amphidromus, enantiomorphy has probably been maintained throughout the history of phylogenetic radiation (Sutcharit et al, 2007), presumably by disassortative mating between the morphs .…”

Early Miocene gastropod and ectothermic vertebrate remains from the Lesvos Petrified Forest (Greece)

“…Gastropod taxonomy follows Bouchet and Rocroi (2005), Wade et al (2006) and the FreshGEN database (Neubauer et al 2014). The terminology and the morphotypes for the fish pharyngeal teeth follow Nakajima (1984), Böhme (2002) and Pasco-Viel et al (2010).…”

Posición evolutiva de caracoles terrestres peruanos (Orthalicidae) entre los Stylommatophora (Mollusca: Gastropoda)

“…y dos de Scutalus versicolor, fueron alineadas junto con otras 26 secuencias de Stylommatophora y dos de pulmonados no-Stylommatophora obtenidas en el GenBank (Tabla 2). De todas las secuencias del gen 16S rRNA disponibles, fueron seleccionados taxa representantes de caracoles pulmonados terrestres del suborden Stylommatophora (Wade et al 2006); se encontró sólo una secuencia de la superfamilia Orthalicoidea, correspondiente a Placostylus (Placostylidae); las secuencias seleccionadas pertenecen tan solo al clado "no-achatinoideo" pues no se encontraban disponibles representantes del clado "achatinodeo". Se usó a los dos pulmonados no-estilommatóforos (Carychium minimum y Siphonaria pectinata) como grupo externo.…”