[Herpetology • 2022] Delma vescolineata • A New Species of Delma Gray 1831 (Squamata: Pygopodidae) from the Hunter Valley and Liverpool Plains of New South Wales

 Delma vescolineata 

 Mahony, Cutajar & Rowley, 2022

 

DOI: 10.11646/zootaxa.5162.5.5 

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Abstract

The Striped Legless Lizard Delma impar Fischer 1882 occurs in grasslands of south-eastern Australia where it is sometimes sympatric with several congeners. Previous molecular analyses have revealed mitochondrial divergence between the northern and southern lineages of D. impar, but the status of a recently detected population assigned to the species in the Hunter Valley of New South Wales (NSW), 250 km north of other populations, remains unknown. Via morphological and molecular analyses across the known distribution of D. impar, we distinguish the population from the Hunter Valley, Liverpool Plains region as a unique taxon and describe this species as Delma vescolineata sp. nov. The new species is divergent from D. impar in both nuclear and mitochondrial analysis, and differing facial scalation and colour patterning from the limited number of specimens available. The degree of mitochondrial and nuclear divergence between the previously identified northern and southern clades of D. impar is consistent with a single species. This is the first description of a Delma from south-eastern Australia since 1974, but the second new vertebrate taxon identified from the Hunter Valley region within a decade. Our research highlights our incomplete understanding of the biodiversity of the Hunter Valley region, despite its relative proximity to populous areas. The range of D. vescolineata sp. nov. is restricted and heavily overlaps with major habitat modification including mining and grazing, with no parks or reserves in this distribution protecting the species’ grassland habitat. Gathering more data to understand conservation status of this species should be a priority.

Reptilia, Delma impar, Delma vescolineata sp. nov., mtDNA, single nucleotide polymorphisms, phylogenetic analysis, grasslands, Reptilia, Australia

Delma vescolineata sp. nov.

   Stephen Mahony, Timothy Cutajar and Jodi J. L. Rowley. 2022. A New Species of Delma Gray 1831 (Squamata: Pygopodidae) from the Hunter Valley and Liverpool Plains of New South Wales.  Zootaxa. 5162(5); 541-556. DOI: 10.11646/zootaxa.5162.5.5 

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A New South Wales first! New species of legless lizard discovered in the Hunter Valley

 australian.museum/blog/amri-news/a-new-south-wales-first-new-species-of-legless-lizard

[Herpetology • 2016] Mitochondrial Introgression via Ancient Hybridization, and Systematics of the Australian Endemic Pygopodid Gecko genus Delma

Fig. 3. Geographic distributions and interspecific relationships within major species groups:
(A) Delma australis group and D. concinna, image of Delma hebesa from Fitzgerald River National Park, WA;
(B) ‘inornate’ group, and image of Delma nasuta from Pannawonica, WA;
(C) D. mitella, and morphologically similar D. fraseri and D. plebeia groups, image of Delma fraseri from Kalbarri, WA;
(D) northwestern Australia group and D. labialis, image of Delma borea from El Questro Station, WA.
 (E) shows extent of the Australian arid zone in grey, and proposed Miocene shrubland corridors adapted from Cracraft (1986), with image of potential vegetative corridor, Acacia and Eucalyptus canopy with tussock grass and shrubby understory from near Kellerberrin, WA. All photos courtesy of Ryan Ellis.

DOI: 10.1016/j.ympev.2015.10.005

Highlights

• Molecular phylogenetic methods identify four major species groups within Delma.

• Multiple instances of hybridization belie previous phylogenetic assessment.

• Most species lineages are young, diverging <10 MYA, during Miocene aridification.

• Further work towards understanding species boundaries in Delma is necessary.

Abstract

Of the more than 1500 species of geckos found across six continents, few remain as unfamiliar as the pygopodids – Family Pygopodidae (Gray, 1845). These gekkotans are limited to Australia (44 species) and New Guinea (2 species), but have diverged extensively into the most ecologically diverse limbless radiation save Serpentes. Current phylogenetic understanding of the family has relied almost exclusively on two works, which have produced and synthesized an immense amount of morphological, geographical, and molecular data. However, current interspecific relationships within the largest genus Delma Gray 1831 are based chiefly upon data from two mitochondrial loci (16s, ND2). Here, we reevaluate the interspecific relationships within the genus Delma using two mitochondrial and four nuclear loci (RAG1, MXRA5, MOS, DYNLL1), and identify points of strong conflict between nuclear and mitochondrial genomic data. We address mito-nuclear discordance, and remedy this conflict by recognizing several points of mitochondrial introgression as the result of ancient hybridization events. Owing to the legacy value and intraspecific informativeness, we suggest the continued use of ND2 as a phylogenetic marker. Results identify strong support for species groups, but relationships among these clades, and the placement of several enigmatic taxa remain uncertain. We suggest a more careful review of Delma australis and the ‘northwest Australia’ clade. Accurately assessing and addressing species richness and relationships within this endemic Australian Gekkotan genus is relevant for understanding patterns of squamate speciation across the region.

Keywords: Mitochondrial capture; Introgression; Biogeography; Pygopodidae; Gekkota

Ian G. Brennan, Aaron M. Bauer and Todd R. Jackman. 2016. Mitochondrial Introgression via Ancient Hybridization, and Systematics of the Australian Endemic Pygopodid Gecko genus Delma.  Molecular Phylogenetics and Evolution. 94, Part B; 577–590. DOI: 10.1016/j.ympev.2015.10.005