Youwanjela, a new genus of land snail from the Kimberley, Western Australia (Eupulmonata, Camaenidae)

2013

Zool J Linn Soc

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Continuing the revision of the Camaenidae in the Australian Monsoon Tropics, we employed comparative analyses of morphological features (with a focus on shell and penial anatomy) and genetic markers (with a focus on mitochondrial COI and 16S sequences) to address the systematic relationships of land snails from the Victoria River District, Northern Territory, and adjacent East Kimberley (Western Australia). These analyses revealed that the species under study represented the previously undescribed genus Nanotrachia. This genus differs from all other camaenid genera known from north‐western Australia most conspicuously by its small, flat, and ribbed shell. Six species are identified as members of the new genus, four of them new species (Nanotrachia costulata sp. nov., Nanotrachia carinata sp. nov., Nanotrachia coronata sp. nov., Nanotrachia levis sp. nov.). Two further species have already been described previously but assigned to different genera. These species, Ordtrachia intermedia (as the type species of Nanotrachia) and Mouldingia orientalis, are here transferred to Nanotrachia. Like other camaenids from the Australian Monsoon Tropics, species of Nanotrachia are characterized by essentially allopatric distributions, regional endemism, and a patchy distribution across their range. © 2013 The Linnean Society of London

Section: Discussionmentioning

confidence: 99%

Small snails in a big place: a radiation in the semi-arid rangelands in northern Australia (Eupulmonata, Camaenidae,Nanotrachia gen. nov.)

2013

Zool J Linn Soc

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“…Only Ordtrachia and Prototrachia exhibit a similar epiphallus–penis configuration, but these groups differ clearly in their penial wall and shell sculpture (Solem, 1984). For a comparison of morphological characteristics in camaenids from the Kimberley see Köhler (2011b), in the newly described genus Youwanjela see Köhler & Shea (2012), in Parglogenia and Arnemelassa from Arnhemland see Köhler (2012), and in Northern Territory camaenids, such as Turgenitubulus , Ningbingia , and Mesodontrachia , see Solem (1981a, b, 1985).…”

Section: Discussionmentioning

confidence: 99%

“…As vast landscapes throughout the monsoonal tropics of Western Australia, the Northern Territory, and Queensland remain poorly studied, it is unclear whether land snail faunas in more arid regions are indeed depauperate or, alternatively, just poorly documented. Whereas regional land snail faunas were comprehensively studied along the eastern and western coastlines of the continent (Solem, 1981a, b, 1984, 1985, 1992, 1997; Stanisic et al ., 2010; Köhler, 2010a, b, 2011a, 2012; Köhler & Shea, 2012), vast areas in the interiors of the Northern Territory, Western Australia, and Queensland remained unstudied. The present knowledge of land snails in the Northern Territory, for instance, rests on late 20 th century revisions that are based on anecdotal historical accounts and collections undertaken along major roads that cover only a small fraction of the Territory's surface (Solem, 1984, 1985, 1993).…”

Section: Introductionmentioning

confidence: 99%

Land snail diversity in the monsoon tropics of Northern Australia: revision of the genusExiligadaIredale, 1939 (Mollusca: Pulmonata: Camaenidae), with description of 13 new species

Law

Zoological Journal of the Linnean Society

2012

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Vast parts of the monsoon tropics of Australia feature semi-arid habitats, which are generally thought to harbour a depauperate land snail fauna as compared to the mesic continental fringes, in particular the Australian wet tropics. However, our knowledge of land snails inhabiting these often remote environments is still very patchy. In order to improve the understanding of land snail diversity in the monsoon tropics, we revised the camaenid land snail genus Exiligada based on comprehensive collections, undertaken by use of helicopters on remote limestone outcrops in the Northern Territory and in Western Australia. Based on comparative analyses of shell and genital morphology and patterns of molecular differentiation, we recognize 15 species within Exiligada, 13 of which are newly described. In addition, we suggest a revised delimitation of the type species Exiligada negriensis, as compared to the latest available revision, by removing Exiligada qualis from its synonymy and recognizing it as a distinct species. A key for species identification is also provided. Molecular phylogenetic analyses strongly supported the monophyly of Exiligada with respect to other confamilial genera known to occur in the same geographical region. Most Exiligada species are narrowly endemic to restricted limestone outcrops that cover areas with a diameter of about 20 to 150 km. Within the distributional range of Exiligada, the ranges of up to seven species overlap but we never found more than three species to occur in sympatry at a given sampling site. We propose that species originated by allopatric differentiation, followed by secondary range expansion, leading to sympatric distributions. Our study confirms that less complex rock habitats in more xeric environments support no more than three sympatric species, this being likely to be a result of ecological exclusion.

“…Fifteen camaenid genera are represented in this part of the Kimberley, several of which are exclusively found here, such as Youwanjela Köhler and Shea, (Köhler and Shea ). Amongst these endemic camaenids of the high rainfall zone, the taxonomy of three presumably closely related genera is revised, Baudinella Thiele, , Retroterra Solem, , and Molema Köhler, 2011.…”

Section: Introductionmentioning

confidence: 92%

Molecular phylogeny and taxonomic revision of the genera Baudinella Thiele, 1931, Retroterra Solem, 1985 and Molema Köhler, 2011 endemic to the coastal Kimberley, Western Australia (Gastropoda, Camaenidae)

2014

J Zoolog Syst Evol Res

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Baudinella Thiele, 1931, Retroterra Solem, 1985 and Molema Köhler, 2011 are three genera of camaenid land snail endemic to coastal regions of the Western Australian Kimberley. Each of these genera has fairly distinct shells, but all exhibit a rather similar configuration of the reproductive system, which is characterized by lack of a penial sheath and presence of an elongated and coiled bursa copulatrix. By combining comparative morphology of shell and penial anatomy with analyses of the mitochondrial DNA fragments 16S rRNA (16S) and cytochrome c oxidase subunit 1 (COI), the phylogenetic relationships amongst representative species of these genera are addressed to test the monophyly of taxa and to identify new species. Our results show that all three genera are members of a single camaenid radiation. Five new species are described: two new species of Baudinella, B. magna n. sp. from the Institute and Montesquieu Archipelagos and B. margaritata n. sp. from Pitta Gorge in the Prince Regent Reserve, one new species of Molema, Molema tenuicostata n. sp., from near Talbot Bay, and two new species of Retroterra, R. dichroma, and R. nana, from the Prince Regent Reserve.