Maringma Tepui Sipo

description

Description of the holotype. A subadult female (according to oviduct development), in good condition, TTL 720 mm, SVL 500 mm, TL 220 mm (30.6 % TTL); head well distinct from neck, narrow anteriorly, widest at temporal region, HW 54.8 % of HL; snout rounded in dorsal and lateral view, SL 6.2 mm; eye large (EL 4.8 mm), pupil round, EN 19.3 % HL; rostral large, broader than long (width about 1.8 times height), visible from above; internasals squarish, as broad as long, slightly smaller than prefrontals, laterally in contact with nasal, their medial suture asymmetrical, noticeably sinistral to the prefrontal medial suture; prefrontals slightly larger than internasals, width 1.5 times length, irregularly hexagonal, separated from eye by preocular and supraocular; frontal pentagonal, bell-shaped, longer than wide, 3.0 times length of medial prefrontal suture; parietals large, length 1.5 times maximal width, medial suture of parietals and length of frontal equal; 5 postcephalic scales. Nasal scale partially divided dorsally and ventrally, posterior part as long as, but slightly higher than, anterior part; preocular 1 / 1, separated from frontal by prefrontal-subocular contact; loreal slig

A new species of Chironius Fitzinger, 1826 (Squamata: Colubridae) from the Pantepui region, northeastern South America

distribution

Distribution and ecology. Based on museum specimens, Chironius challenger is known between 1400 – 2088 m elevation from three localities in the eastern Pantepui region: Auyantepui in Venezuela, Maringma Tepui and Mount Wokomung in Guyana (Fig. 5). An additional specimen collected at 1520 m elevation on the summit of Guaiquinima Tepui, Venezuela (Fig. 5) is illustrated in Mägdefrau et al. (1991: 22, 23) under C. fuscus (see Discussion and additional comparisons). The holotype was collected in the morning while it was moving in a small tree about 200 cm above the ground in low evergreen upper-montane forest. ROM 42603 was collected while moving on the ground on the northeastern slope of Mount Wokomung, also in low evergreen upper-montane forest. No data on microhabitat is available for the two other referred specimens, which are presumably from low evergreen upper-montane or high-tepui forest according to the collection localities. The specimen reported by Mägdefrau et al. (1991) from Guaiquinima Tepui was collected in the afternoon, on a rock on the bank of a stream dissecting a rocky area covered by Stegolepis (Rapateaceae) and small patches of forest (presumably high-tepui forest

A new species of Chironius Fitzinger, 1826 (Squamata: Colubridae) from the Pantepui region, northeastern South America

etymology

Etymology. The specific epithet is considered to be a noun in apposition and refers to Professor George Edward Challenger, the fictional main character of Sir Arthur Conan Doyle's famous novel " The Lost World " published in 1912. " The Lost World " depicts an epic expedition to an isolated tepui in the middle of the tropical jungle of northern South America in search of dinosaur-like creatures and a forgotten civilisation. The reading of Sir Conan Doyle’s novel when I was a child fuelled my thirst for exploration and adventure and positively influenced my research and interest in the Pantepui region. Definition and diagnosis. A species of the genus Chironius characterized by the following combination of characters: 10 dorsal scale rows at midbody, absence of apical pits and paravertebral keels in female (male unknown), 152 – 159 ventrals, 99 – 103 subcaudals, anal plate single, loreal as long as — or slightly longer than — high, 39 – 41 maxillary teeth. Only five of the 20 currently known Chironius species occur in the Guiana Shield (area sensu Ávila-Pires 2005, number of species f i de Hollis 2006): C. carinatus (Linnaeus, 1758), C. cochranae Hoge and Romano, 1969, C. exoletus (L

A new species of Chironius Fitzinger, 1826 (Squamata: Colubridae) from the Pantepui region, northeastern South America

materials_examined

Holotype. IRSNB 2659 (field number PK 2017), a subadult female collected by Philippe J. R. Kok, 25 November 2007 at 10 h 45, southeastern slope of Maringma Tepui, Cuyuni-Mazaruni District, Guyana (05 ° 12 ’ N, 060 ° 35 ’ W, 1500 m elevation). Referred specimens. BMNH 1976.235, adult female collected by Adrian Warren, 17 August 1974, southern side of Auyantepui, 2088 m elevation, Venezuela; ROM 42603, juvenile collected by Samir Khan, 2 November 2004, Mount Wokomung, 1400 m elevation, Guyana; MHNLS 16088, subadult female collected by Gilson Rivas, 8 February 2002, Auyantepui, 1700 m elevation, Venezuela.

A new species of Chironius Fitzinger, 1826 (Squamata: Colubridae) from the Pantepui region, northeastern South America