Contomastix charrua

[sebastian]

A new, but probably extinct, species of Cnemidophorus (Squamata, Teiidae) from Uruguay.

Mario R. Cabrera & Santiago Carreira

A new species of Cnemidophorus related to the lacertoides group is described. The new taxon is distinguished from all other species of the genus by the following combination of character states: 81–98 granular dorsal scales across midbody; 201–206 dorsal scales along midline from nape to rump in males, 208–229 in females; 10 longitudinal rows of ventral scales in both sexes; 19–22 femoral pores in total; 13–15 subdigital lamellae under fourth finger, 20–25 lamellae under fourth toe; 3–4 supraoculars on each side; reduced expression of the “lacertoides pattern”, which may be absent and replaced by a broad greenish mid-dorsal stripe on a brownish-grey background; ventral surfaces of head, body, limbs and tail pearly white, with the most lateral ventral scales of the body completely dark along the belly. The new species also exhibits some anatomical differences from its most closest related species, C. lacertoides. The hyobranchial apparatus of Cnemidophorus new sp. has a pair of short cartilaginous second ceratobranchials, articulated behind the basihyal–first ceratobranchial joint. This structure is absent in the hyobranchial apparatus of C. lacertoides sensu stricto which, moreover, has hypohyals that are relatively longer than in the new species. The new taxon is known only from the type locality, Cabo Polonio, Rocha Department, on the Atlantic coast of Uruguay, in a habitat of rocky grassland. Records of individuals are lacking from three decades to date and detailed field surveys in recent years in search of the lizard were unfruitful. We assume that this taxon is probably extinct. The pressure of increased human presence on the limited suitable habitat in the Cabo Polonio region could have caused its extinction.

Key words: Cnemidophorus lacertoides, extinction, new species, taxonomy

HERPETOLOGICAL JOURNAL 19: 97–105, 2009

[sebastian]

Photo of the specimens in the following pdf (page 14):

www.szu.org.uy/noticias/noticias_szu_02_06.pdf

[Peter]

Thanks for sharing this and good to see you here again Sebastian!

[Sebbe]

A lost species or the loss of stripes? The case of Contomastix lizards from Cabo Polonio, Uruguay, with observations on C. lacertoides(Duméril & Bibron)and Cnemidophorus grandensis Cope (Squamata, Teiidae)

www.mapress.com/zootaxa/2013/f/z03620p259f.pdf

This species is now considered to be a synonym of C. lacertoides.

[Melanie]

Valid species according to the IUCN


Scientific Name: Contomastix charrua
Species Authority: Cabrera & Carreira, 2009
Taxonomic Notes: This species, described from within Cnemidophorus (now Contomastix) lacertoides on the basis of differences in coloration, structure of the hyoid apparatus and geological history of the cape (Cabrera and Carreira 2009). Borteiro et al. (2013) found no morphological differences between the two taxa and referred C. charrua to the the synonymy of C. lacertoides. S. Carreira (pers. comm. 2016) indicates that ongoing research has identified additional differences that may warrant recognizing C. charrua as a separate species. Additionally, S. Carreira (pers. comm. 2016) note that C. lacertoides is likely to represent a species complex, and proposes retaining C. charrua as a valid species pending comparison with material from the C. lacertoides type locality, which was not done by Borteiro et al. (2013).
Assessment Information [top]
Red List Category & Criteria: Extinct ver 3.1
Year Published: 2016
Date Assessed: 2014-11-12
Assessor(s): Carreira, S.
Reviewer(s): Bowles, P.
Facilitator/Compiler(s): Rodríguez, J. & NatureServe
Justification:
Different systematic searches have been made without success to find the species since its last record in 1977. Therefore it is listed as Extinct. It seems likely that the increasing human settlement of Cabo Polonio by people, the actions of domestic predatory animals, and disturbance resulting from tourism, particularly during the breeding season, were all factors contributing to its extinction.
Geographic Range [top]
Range Description: Contomastix charrua was known only from Cabo Polonio, southern Uruguay (Cabrera and Carreira 2009, Borteiro et al. 2013). It is believed to be extinct (Cabrera and Carreira 2009). Cabo Polonio is no more than 15 m asl (Borteiro et al. 2013).
Countries occurrence:
Regionally extinct:
Uruguay
Additional data:
♦ Lower elevation limit (metres): 15
♦ Upper elevation limit (metres): 15
Range Map: Click here to open the map viewer and explore range.
Population [top]
Population: This lizard is thought to be extinct. The last record is from the 1977 (Cabrera and Carreira 2009). Federico Achaval discovered this population, at the time considered conspecific with C. lacertoides. Besides this researcher's efforts (probably more than 30 days of surveys in each of the past 20 years) to locate this species, several systematic surveys have been carried on the area in the decades following its discovery but the species has not been located since then.
Additional data:
Habitat and Ecology [top]
Habitat and Ecology: Cabo Polonio is a small coastal granitic outcrop of about 0.2 km2 with sandy soil (Borteiro et al. 2013).
Systems: Terrestrial
Use and Trade [top]
Use and Trade:

This species was not utilized or traded.
Threats [top]
Major Threat(s): It seems likely that the increasing human settlement of Cabo Polonio by people, with an attendant increase in the numbers of predatory dogs and cats, and massive tourism, particularly during the summer months (the lizards’ reproductive season) could have caused its extinction (Cabrera and Carreira 2009).
Conservation Actions [top]
Conservation Actions: It was a priority species for conservation in Uruguay (Carreira and Estrades 2013), but was considered extinct by Carreira and Maneyro (2015). It was found in Cabo Polonio National Park. Taxonomic research is required to emsure that this species is not conspecific with another extant taxon (see Taxonomic Notes).

www.iucnredlist.org/details/63488699/0