Rhagadarevisited: on the taxonomy of species from the Kimberley and Dampierland, Western Australia (Pulmonata, Camaenidae)

Abstract

The genus Rhagada is the second most diverse camaenid genus in Australia. We examined anatomical and mitochondrial characters of previously unidentified material from the Kimberley that was earmarked to potentially represent new species in recently published molecular phylogenetic studies. Our comparisons revealed that specimens from Gibbings Island ('R. sp. Gibbings') were morphologically and genetically most similar to Rhagada cygna from the Dampier Peninsula. Hence, 'R. sp. Gibbings' is considered to be identical to R. cygna. In addition, we found that R. cygna as so delimited is not clearly distinguished from the second species on the Dampier Peninsula, Rhagada bulgana. Both species differ rather subtly in anatomical and mitochondrial characters, indicating their close relationships and potentially incomplete evolutionary differentiation. Furthermore, we describe two new species based on comparative morphology and mitochondrial sequences: Rhagada worora n. sp. from the Prince Regent Reserve in the Kimberley and Rhagada karajarri n. sp. from Dampierland. The present study confirms that species in Rhagada are best identified by means of both morphological and molecular data.http://zoobank.org/urn:lsid:zoobank.

Molecular phylogenetics and systematic revision of the south-eastern Australian Helicarionidae (Gastropoda, Stylommatophora)

“…Species delimited by their morphology were consistently found to form monophyletic clusters in the mitochondrial trees, which usually were well separated from each other by long basal branches. The amounts of interspecific genetic differentiation observed here were at the lower end of the rather wide spectrum of average interspecific differences among stylommatophoran land snails (Davison et al, 2009;Criscione et al, 2012;Köhler and Johnson, 2012;Criscione and Köhler, 2013b;Burghardt and Köhler, 2014). In addition, there has been considerable overlap between the ranges of intraspecific and interspecific distances in the southeastern Australian helicarionids, particularly in 16S (Fig.…”

A mitochondrial phylogeny uncovers taxonomic ambiguity and complex phylogeographic patterns in the eastern Australian land snail Austrochloritis (Stylommatophora, Camaenidae)

“…Nevertheless, we consider the available mitochondrial evidence as an overall reliable indicator for the systematic relationships within this group and for the need to critically revisit the current species‐level taxonomy. This conclusion is based on an extensive body of literature that underpins the systematic utility and reliability of mtDNA markers in Australian camaenids (e.g., Burghardt & Köhler, 2014; Criscione & Köhler, 2014a, 2014b, 2016a, 2016b; Köhler & Burghardt, 2015; O'Neill, Johnson, Hamilton, & Teale, 2014) as well as the observation of a marked phylogeographic structure in the phylogenetic tree (Figure 3). However, the discrepancy between BI and ML topologies and relatively low basal branch support values for many nodes indicate difficulties in reliably resolving more ancient splits among Austrochloritis species.…”

Initiation of speciation across multiple dimensions in a rock‐restricted, tropical lizard

“…The level of lineage diversity exhibited by H. planiceps across such a relatively small region is exceptional, even exceeding that within the Heteronotia spelea complex, which is similarly rock‐dwelling but spans a considerably larger area across the Australian arid zone (Figure 1 ). Indeed, lineage diversity in H. planiceps approaches the scale of short‐range endemism observed in some groups of terrestrial snails in the Kimberley (Koehler, 2010 ). This is highlighted further by the lower level of phylogeographical structuring observed in the H. binoei complex, individuals of which are common in grassland and open woodland as well as rocky habitats—a pattern mirrored in rock‐dwelling versus tree‐dwelling Gehyra geckos in the region (Oliver et al, 2019 ).…”