Tuesday, June 7, 2022

[Herpetology • 2022] Ctenotus kutjupa • A New Lizard Species (Scincidae: Ctenotus) highlights persistent Knowledge Gaps on the Biodiversity of Australia’s central Deserts

Ctenotus kutjupa 
Prates, Hutchinson, Huey, Hillyer & Rabosky, 2022

Pictures by Ryan Ellis & John Harris.

Australia harbors the most diverse lizard assemblages on Earth, yet the biodiversity of its vast arid zone remains incompletely characterized. Recent sampling of remote regions has revealed new species with unique phenotypes and unclear evolutionary affinities. Here, we describe a new species of scincid lizard that appears to be widely distributed across the Great Victoria Desert and adjacent regions. The new species was previously overlooked among specimens of the wide-ranging desert taxon Ctenotus schomburgkii but is distinguished from it by coloration and scalation characters. Phylogenetic analyses based on mitochondrial and genome-wide nuclear loci confirmed that the new species is highly divergent from C. schomburgkii, with which it appears to be sympatric across much of its range. In addition to the new species, our survey of genetic variation within C. schomburgkii as currently recognized revealed three additional lineages that approach one another in southern and northwestern Australia, and which may also represent distinct species. These results suggest that our knowledge of the extraordinary biodiversity of arid Australia remains incomplete, with implications for the conservation and management of this unique fauna. The targeted collection of voucher specimens in undersampled regions, coupled with population genetic screening of lineage diversity, will be crucial for characterizing species boundaries and understanding the composition of Australia’s vertebrate communities.

Keywords: cryptic species, population genetics, phylogeography, arid zone, Ctenotus schomburgkii

Coloration in life.
a) Paratype of Ctenotus kutjupa sp. nov. (WAM R175023) from around Beyondie Lakes,  Western  Australia  (WA).  Picture  by  Ryan  Ellis.  b)  C. kutjupa from  the  Tjirrkarli  Aboriginal  Lands, Gibson Desert, WA. Picture by John Harris.

c) Ctenotus schomburgkii from Goongarrie National Park, WA. Picture by Daniel L. Rabosky. d) Ctenotus schomburgkii from Gluepot, South Australia. Picture by Kym Nicolson.

 e) Schematic representation of dorsal color pattern in C. kutjupa and C. schomburgkii in localities where they co-occur (see text). Note the continuous dark line down the middle of the scale row 1 in C. kutjupa (arrows).

Ctenotus kutjupa sp. nov. Hutchinson, Prates & Rabosky

Diagnosis: A small species of Ctenotus characterized by the unique combination of sharp-edged and spinose subdigital lamellae, a pre-subocular scale between the lower preocular and the subocular supralabial, and prefrontal and nasal head shields usually in medial contact (Fig. 3b). The color pattern typically includes seven narrow dark dorsal stripes, including a vertebral stripe that becomes more prominent on the (unbroken) tail and runs almost the full length of the tail in most individuals (Fig. 3a). The new species is further characterized by the combination of a dark upper lateral zone with a single series of large pale spots with an ascending series of black and whitish blotches that curve dorsally behind the eye (Fig. 4a–b, e).

 Ctenotus kutjupa sp. nov. distribution and habitat.
a) Localities where C. kutjupa is presently known to occur. Distribution of deserts and xeric shrublands (i.e., the arid zone’s driest portion) as per Olson et al. (2001).
 b) Habitat east of the Pungkulpirri Waterhole, Western Australia (WA), collection site of holotype WAM R166437. Picture by Helen Vonow.
c) Habitat in the vicinity of the Beyondie Lakes, WA, collection site of C. kutjupa paratype WAM R175023. Picture by Ryan Ellis.

Etymology: The word kutjupa, meaning “the other one” or “another one” in its noun form, makes reference to the discovery of the new species among collections of C. schomburgkii. We use this word, shared by several Western Desert languages (e.g., Maralinga Tjarutja, Yankunytjatjara, Pitjantjatjara, Ngaanyatjarra), to acknowledge that this lizard belongs to the country where these languages are spoken. The specific epithet is a noun in apposition to the genus. 

Ivan Prates, Mark N. Hutchinson, Joel A. Huey, Mia J. Hillyer and Daniel L. Rabosky. 2022. A New Lizard Species (Scincidae: Ctenotus) highlights persistent Knowledge Gaps on the Biodiversity of Australia’s central Deserts. Bulletin of the Society of Systematic Biologists. 1(2):8720. DOI: 10.18061/bssb.v1i2.8720