Trachylepis gonwouoi Allen, Tapondjou, Welton & Bauer

Allen, Kaitlin E., Tapondjou, Walter P., Welton, Luke J. & Bauer, Aaron M., 2017, A new species of Trachylepis (Squamata: Scincidae) from Central Africa and a key to the Trachylepis of West and Central Africa, Zootaxa 4268 (2), pp. 255-269 : 258-261

Trachylepis gonwouoi Allen, Tapondjou, Welton & Bauer sp. nov.

Holotype. California Academy of Sciences , San Francisco, CA: CAS 261092 , adult male, collected near the town of Mudeka near Mt . Cameroon, Southwest Region , Cameroon, 4.125°N, 9.491°E, 16 June 2014, by Kaitlin Allen, Walter Tapondjou and Luke Welton ( Fig. 2 ).

Paratypes. Monte L. Bean Life Science Museum, Provo, Utah and California Academy of Sciences, San Francisco, CA: CAS 261090 , juvenile, town of Buea near Mt. Cameroon, Southwest Region, Cameroon, 4.160°N, 9.228°E ; CAS 261091 , female and BYU 573522 , female, town of Idenau , Southwest Region, Cameroon 4.183°N, 9.000°E ; CAS 261093, juvenile, BYU 573527, juvenile, BYU 573861, juvenile, BYU 573529 , female, and BYU 573530 , male, town of Nyasoso on Mt. Kupe, Southwest Region, Cameroon, 4.823°N, 9.670°E; 14 June 2016 – 2 July 2016; coll. Kaitlin Allen, Walter Tapondjou and Luke Welton. ( Fig. 3 and Fig. 4 )

Other material referred. Additional specimens referable to the new species based on mitochondrial genotype are: United States National Museum of Natural History ( USNM) 584340, town of Impongui, Likouala Province, Republic of the Congo, 1.079°N, 17.036°E ; Zoologisches Forschungsmuseum Alexander Koenig , Bonn ( ZFMK) 68962 and 75386, Mt. Nlonako, Littoral Region, Cameroon, 4.906°N, 9.951°E ; and ZFMK 87654 , Campo Reserve , South Province, Cameroon, 2.337°N, 9.857°E ; Museum für Naturkunde [no voucher collected], Mt. Nlonako, Littoral Region, Cameroon, 4.906°N, 9.951°E ; and [no voucher collected], Rumpi Hills , Southwest Region, Cameroon, 4.898°N, 9.119°E ( Fig. 4 ).

Diagnosis. Trachylepis gonwouoi sp. nov. can be distinguished from other Trachylepis in West and Central Africa by the following characteristics, number of keels on dorsal scales (3–5); moderate SVL (maximum size of 80 mm); number of scale rows at midbody (28–34); number of supracilliaries (6–10); presence of a well defined lateral white stripe extending from beneath eye to insertion of hind limb, bordered by black; and ventral color in life bright blue-green.

Description of the holotype. Adult male specimen; tail regenerated; right parietal scale missing, replaced by scar tissue; some damage to scales on right side of neck; SVL 71 mm; regenerated tail length 101 mm, approximately 1.4 times SVL; head depth 7.6 mm; orbit width 5.7 mm; eye height 3.4 mm; distance from anterior portion of tympanum to tip of snout 16 mm; distance from rictus to tip of snout 13.1 mm; supralabials 7 (L) 8 (R), fifth supralabial located under eye, widened; infralabials 8 (L) 9 (R); 4 supraoculars; supracilliaries 7 (L) 6 (R); 2 supranasals; 2 loreals, anterior roughly half the size of posterior; prefrontals contact at a medial point; supranasals narrowly separated by rostral and frontonasal; nostril bisects nasal scale into postnasal and prenasal; nuchal scales in broad contact; frontoparietals divided by interparietal plate; frontoparietals of equal length; parietals in broad contact; tympanic aperture large and vertically elongated with two well-developed anterior lobules on each side ( Fig. 5 ); right forelimb length 26 mm; right hind-limb length 34.2 mm (measured to the terminus of the longest digit); axilla–groin distance 37.1 mm; limb scales keeled; digits I and IV entirely missing on left hand; subdigital lamellae Toe IV 15 (L) 18 (R); subdigital lamellae Finger IV 10 (R); scales on ventral surface of manus and pes smooth; 30 transverse scale rows at midbody; dorsal scales with 3–5 keels; 49 paravertebral scales between nuchals and base of tail; 54 ventral scales between the first pair of postmentals and cloaca; 6 precloacal scales smooth, medioventrally widened; caudal scales medio-ventrally widened, smooth; regenerated caudal scales large, carination less distinct.

Coloration (preserved specimen): body dorsum uniformly brown with a lateral white stripe from under the eye to the insertion of the hind limb. White stripe 1 mm (one scale row) wide at midbody, widening to 1.5 mm (1.5 scale rows) near forearm insertion, bordered by thin black stripes, about 0.5 mm thick. Ventrally uniform gray-blue from snout to tail tip, limbs ventrally darker gray-blue, ventral surface of manus and pes black ( Fig. 2 ).

Color in life: Dorsal surface solid brown with no mottling; flanks red-brown to middle of flank; white lateral line (1 to 1.5 mm thick) bordered by two thinner black lines (0.5 mm thick) on flank from snout to insertion of hind limb; ventral quarter of flank and venter from tip of snout to tip of tail blue-green; ventral surface of manus and pes black; eyelid borders yellow and contrasting with surrounding brown scales; eyelids black; eye color dark brown; limbs red-brown; feet darker brown than legs or dorsum ( Fig. 6 ).

Variation. Variation among members of the type series of Trachylepis gonwouoi sp. nov. in mensural and meristic characters are reported in Table 2. The range of variation for each character is reported here: SVL of adults, 71–80 mm; ratio of tail length to body length (for original tails only), 1.787–1.90; ratio of head length to body length, 0.158–0.275; number of scale rows at midbody, 28–34; number of paravertebral scales from nuchals to base of tail, 47–53; number of ventrals from first post-mental pair to the anal plates, 51–61; number of subdigital lamellae for Toe IV, 10–19; number of subdigital lamellae for Finger IV, 9–16; number of supralabials, 6–8; maximum number of keels on dorsal scales, 3–5; supranasials contact at a point or have no contact; prefrontals contact at a point or have no contact; number of supracilliaries, 6–10.

Etymology. This species is a patronym honoring Dr. LeGrand Gonwouo Nono, the first native-born Cameroonian herpetologist, in recognition of his work to increase the knowledge of herpetology and conservation of endangered reptiles and amphibians throughout Cameroon.

Vernacular name. Gonwouo’s skink (English); Scinque de Gonwouo (French).

Distribution. We collected Trachylepis gonwouoi sp. nov. from two areas in the Southwest Province of Cameroon, on Mt. Cameroon, near the towns of Buea (4.160°N, 9.228°E), Idenau (4.183°N, 9.000°E) and Mudeka (4.125°N 9.491°E) and on Mt. Kupe near the town of Nyasoso (4.823°N, 9.670°E). Specimens from the United States National Museum of Natural History (USNM) and the Natural History Museum of Geneva (MHNG) were collected from Mt. Nlonako (4.905°N, 9.951°E), Campo (2.337°N, 9.857°E), and Rumpi Hills (4.898°N, 9.119°E). One specimen has also been collected in the Likouala province of the Congo near the town of Impongui (1.079°N, 17.306°E). The total distance between the two most distant localities is 1008 kilometers ( Fig. 4 ).

Natural history. Trachylepis gonwouoi sp. nov. was associated with disturbed habitat in agricultural and residential areas as well as secondary forest. It was often found in the leaf litter or on the trunks of cocoa trees. Specimens from Cameroon were found at elevations from 50 to 1050m. This species is syntopic with T. affinis and T. maculilabris .

Figures

FIGURE 2. Holotype of Trachylepis gonwouoi sp. nov., CAS 261092 (A) dorsal view, (B) ventral view and (c) lateral view (photo credit: Luke Welton).

FIGURE 3. Paratypes of Trachylepis gonwouoi sp. nov.. A) Dorsal and B) ventral view of each paratype. From left to right: BYU 573522, BYU 573530, CAS 261091, BYU 573529, CAS 261093, BYU 573527, CAS 261090, BYU 573861 (photo credit: Luke Welton).

FIGURE 4. A map of the sampling of Trachylepis gonwouoi sp. nov. Red indicates samples that were collected in 2014 and designated as the type specimens with circles representing paratypes and the red star representing the holotype. Blue indicates localities of additional, non-type samples of T. gonwouoi sp. nov.

FIGURE 5. Head scalation of Trachylepis gonwouoi sp. nov. holotype CAS 261092.

FIGURE 6. Holotype of Trachylepis gonwouoi sp. nov., CAS 261092. Male collected from Mudeka near Mount Cameroon (photo credit: Luke Welton).