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J. Moll. Stud. (2002), 68, 259-281
© The Malacological Society of London
2002
MORPHOLOGICAL REVIEW AND PHYLOGENETIC ANALYSIS OF NODILITTORINA (GASTROPODA: LITTORINIDAE)
Department of Zoology, The Natural History Museum, London SW7 5BD, UK
Correspondence: e-mail: dgr{at}nhm.ac.uk
As presently defined, Nodilittorina is the largest of the genera of Littorinidae, but its taxonomy is under revision, its monophyly is doubtful, and almost nothing is known of the phylogenetic relationships among its species. Here, 60 species are recognized worldwide and their morphological characters (shell, operculum, headfoot, reproductive anatomy, spermatozoa, spawn and development, radula, and alimentary system) reviewed. Twenty-six characters are selected for a parsimony analysis, which includes representatives of all seven of the other genera in the subfamily Littorininae. No character is found to support the monophyly of Nodilittorina. Instead, the genus Littorina is nested within a large clade of Nodilittorina species and there is some evidence for the monophyly of Littorina plus 10 species of Nodilittorina from the southern temperate regions. The remaining, almost exclusively tropical, Nodilittorina species show little morphological differentiation and widespread homoplasy, so that their phylogenetic relationships remain poorly resolved by this analysis.
(Received 10 November 2001; accepted 10 February 2002)