Major adaptive radiation in neritopsine gastropods estimated from 28S rRNA sequences and fossil records

Abstract

A well-supported phylogeny of the Neritopsina, a gastropod superorder archaic in origin, radiated ecologically and diverse in morphology, is reconstructed based on partial 28S rRNA sequences. The result (Neritopsidae (Hydrocenidae (Helicinidae ϩ Neritiliidae) (Neritidae ϩ Phenacolepadidae))) is highly congruent with the fossil records and the character distribution of reproductive tracts in extant taxa. We suggest that the Neritopsina originated in subtidal shallow waters, invaded the land and became fully terrestrial at least three times in different clades, by the extinct Dawsonellidae in the Late Palaeozoic and by the Helicinidae and Hydrocenidae in the Mesozoic. Invasion of fresh-and brackish waters is prevalent among the Neritopsina as the Jurassic and freshwater ancestory is most probable for helicinids. The Phenacolepadidae, a group exclusively inhabiting dysoxic environments, colonized deep-sea hydrothermal vents and seeps in the Late Cretaceous or Early Cenozoic. Submarine caves have served as refuges for the archaic Neritopsidae since the Early to Middle Cenozoic, and the marine neritopsine slug Titiscania represents a highly specialized but relatively recent offshoot of this family. The Neritiliidae is another clade to be found utilizing submarine caves as shelter by the Oligocene; once adapted to the completely dark environment, but some neritiliids have immigrated to surface freshwater habitats.

Pseudamnicola Paulucci, 1878 (Caenogastropoda: Truncatelloidea) from the Aegean Islands: a long or short story?

“…The following primers were used in the study: two mitochondrial gene fragments: (i) COI (with primers: LCOI490 5′-GGTCAACAAATCATAAAGATATTGG-3′; Folmer et al 1 9 9 4 a n d C O R 7 2 2 b 5 ′ -TA A A C T T C A G G G T GACCAAAAAATYA-3′; Wilke and Davis 2000) and (ii) 1 6 S ( p r i m e r s : L R J 1 2 8 8 7 5 ′ -C C G G T C T G A A C T C A G AT C A C G T-3 ′ a n d L R N 1 3 3 9 8 5 ′ -CGCCTGTTTAACAAAAACAT-3′; Kasper et al 2004); two nuclear gene fragments: (iii) 18S (primers: Attwood et al 2003) and ( i v ) 2 8 S ( p r i m e r s : 2 8 S n a 1 5 ′ -G A C C C G T C TTGAAACACGGA-3′ and 28Sna2 5′-AGCCAATCCT TATCCCGAAG-3′, Kano et al 2002); histone 3 (primers: H3F 5′-ATGGCTCGTACCAAGCAGACVGC-3′ and H3R 5′-ATATCCTTRGGCATRATRGTGAC-3′; Colgan et al 1998).…”

Phylogenetic relationships and evolution of pulmonate gastropods (Mollusca): New insights from increased taxon sampling

“…It cannot be excluded that some of those early fossils could simply not be pulmonates, but rather belong to prosobranch taxa, such as Neritopsina, known from terrestrial shells from the late Carboniferous (Kano et al, 2002). They could belong to extinct taxa (a hypothesis that has surprisingly never been considered).…”

Global diversity of gastropods (Gastropoda; Mollusca) in freshwater

“…However, few comprehensive phylogenies for individual families or the higher taxonomic groupings that contain freshwater taxa have been published to date. For those that have been published, variable taxon sampling, incongruence between morphological and molecular data, compounded by weak support of basal nodes, has often resulted in conflicting interpretations concerning the monophyly and/or affinity of freshwater clades and the number of freshwater invasions [e.g., Neritimorpha (Holthuis, 1995;Kano et al, 2002); Architaenioglossa (Colgan et al, 2003;Simone, 2004); Hygrophila (Barker, 2001;Dayrat et al 2001); Cerithioidea (e.g., Lydeard et al, 2002); Rissooidea (see below)]. The large assemblage of marine, brackish and freshwater lineages currently placed in the Rissooidea arguably are in the most urgent need of revision.…”