Phylogenetic analysis of the Camaenidae (Mollusca: Stylommatophora) with special emphasis on the American taxa

Abstract

The monophyly of the land snail family Camaenidae has been in doubt due to a disjunct bihemispheric distributional pattern and to the lack of morphological synapomorphies. A cladistic analysis is presented using an ingroup composed of representatives of the three subfamilies distributed in Australia and 52 other species with American distribution. Bradybaenidae, Helicidae and Helminthoglyptidae were used as outgroups. Fifty morphological characters were treated as unordered and analysed using Pee-Wee ver. 2.9, a program for parsimony analysis using implied weights. The results of the analysis support Camaenidae as a monophyletic family (synapomorphies: oval genital orifice, absence of penial sheath). Two of the three Australasian subfamilies, Sinumeloninae and Camaeninae, are monophyletic in the strict consensus tree. The American taxa are classified in eight genera and arranged into two main clades. Caracolus is proposed as the sister group of the American Continental Camaenidae. The genus Solaropsis, previously excluded from this family by different authors, is reassigned to Camaenidae. Shell characters proved to be phylogenetically informative in defining Pleurodonte, Caracolus, Solaropsis, Isomeria and Labyrinthus.

Divergent Shell Shape as an Antipredator Adaptation in Tropical Land Snails

“…For example, the snail family Camaenidae, which includes Satsuma, is widely diversified in the terrestrial tropics across Southeast Asia, Australia, and Middle America (Scott 1997). The diversity in apertural shape is remarkable and has been regarded as a taxonomically informative character (Cuezzo 2003;Wade et al 2007). However, recent molecular evidence indicates that Camaenidae is nonmonophyletic (Wade et al 2006).…”

Minaselates, a new genus and new species of Epiphragmophoridae from Brazil (Gastropoda: Stylommatophora: Helicoidea)

“…The terminology for the anatomical descriptions follows Tompa (1984). The terms proximal and distal refer to the position of an organ or part of an organ in relation to the gamete flow from the ovotestis (proximal) to the genital pore (distal), as in previous studies (Cuezzo 1997, Cuezzo 2006 For the cladistic analysis, a matrix of 35 characters from the general anatomy plus shell morphology was generated for 24 terminal taxa (Appendix 1), following characters and codifications of Cuezzo (2003) for Pleurodonte Fischer, 1807 and Labyrinthus Beck, 1837 and Cuezzo (2006) for species of Epiphragmophora, with modifications. The characters used in the analysis are listed in Appendix 2.…”

“…It is also similar to some Pleurodontidae in its long and thin kidney, the crowded granules in the surface of the shell protoconch, the globular general shape of the shell, the complex microsculpture on the teleoconch and in its smooth jaw. The presence of a flagellar caecum is noteworthy in Minaselates, this structure being absent in Epiphragmophoridae, while it is characteristic of some Pleurodontidae such as Polydontes Montfort, 1810 and Pleurodonte incerta (Férussac, 1823) (Cuezzo 2003).…”

“…n. the vas deferens runs straight, parallel to the penis complex, without looping around the epiphallus. Most of the Helicoidean families have a ribbed jaw or 'odontognath jaw', except for the Sagdidae with a 'stegognath jaw' and the Sphicterochilidae and Cepoliinae with a smooth jaw ('oxygnath jaw') (Cuezzo 2003). In M. paradoxa sp.…”

“…Only taxa with described anatomy were included in the matrix. Character codification according to Cuezzo (2003Cuezzo ( , 2006 with some modifications. "-"are non-applicable characters, "?"…”