Trachylepis raymondlaurenti Marques, Ceríaco, Bandeira, Pauwels & Bauer, 2019

Marques, Mariana P., Ceríaco, Luis M. P., Bandeira, Suzana, Pauwels, Olivier S. G. & Bauer, Aaron M., 2019, Description of a new long-tailed skink (Scincidae: Trachylepis) from Angola and the Democratic Republic of the Congo, Zootaxa 4568 (1), pp. 51-68 : 59-62

Trachylepis raymondlaurenti Marques, Ceríaco, Bandeira, Pauwels & Bauer sp. nov.

( Figs. 5 , 6 )

Mabuya megalura (de Witte 1953: 107)

Mabuya megalura subsp. ( Laurent 1964: 74)

Trachylepis megalura ( Broadley & Cotterill 2004: 42 [partim])

Trachylepis cf. megalura ( Ceríaco et al. 2016b: 71; 2018b: 423; Marques et al. 2018: 264)

Holotype. CAS 258401 ( Figs. 5 , 6 ), adult female collected in the Giant Sable Sanctuary of Cangandala National Park (- 9.84606° N, 16.7223° E, WGS-84; elevation 1101 m above sea level) ( Fig. 4 ), Malanje Province, Angola, by Mariana Marques , Luis Ceríaco , Suzana Bandeira , Edward Stanley and Jens Vindum on 17 September 2015.

Paratypes. MD 5309 , adult female collected in Alto Cuílo (- 10.01667° N, 19.55° E, WGS-84; elevation 1101 m), Lunda Sul Province, Angola, by a local in June 1954 ; MCZ R-67627, adult female with the same collection data as the former ; RBINS 2691 (formerly RBINS 6998 ), adult female collected in Lusinga (- 8.933333° N, 27.2° E, WGS-84; elevation 1810 m), Upemba National Park, DRC, during the Mission G. - F. de Witte on 16 March 1947 ; RBINS 2692 (formerly RBINS 6999 ), adult male with locality data as for the former but collected on 9–17 April 1947 ; RBINS 2693 (formerly RBINS 7000 ), adult male with locality data as for RBINS 2691 but collected on 21 June–21 July 1947 ; RBINS 2694 (formerly RBINS 7001 ), adult male with the same locality data as for RBINS 2691 but collected in December 1947 ; RBINS 2695 (formerly RBINS 7002 ), adult female with the same locality data as for RBINS 2691 but collected in January 1948 .

Diagnosis. Trachylepis raymondlaurenti sp. nov. is readily distinguished from all other congeners by the following combination of characters: (1) slender body of medium size, SVL up to 79.3 mm; (2) long-tailed, up to 215.8 mm, greater than twice body length; (3) well-defined neck constriction; (4) color homogeneously greyishbrown dorsally, with some dark speckles on sides of tail; ventral surface with some scattered dark speckles near the flanks and under the tail; supralabials and infralabials dotted with white; no distinct longitudinal or transverse dorsal bands; (5) MSR 24–28, SAD 48–53, SAV 50–58; (6) KDS 0–3; (7) scales on palms of hands and soles of feet smooth; (8) supranasals separated; and (9) prefrontals separated.

Holotype description. Individual in good condition. Gravid female, with 10 fetuses in advanced stage of development. Habitus and relative sizes of head, body and tail comparable to Trachylepis megalura . Body cylindrical and slender with a well-defined neck and thin limbs; tail very long, its length greater than twice the SVL, smoothly tapering. Fore- and hind limbs overlap when depressed against the body. SVL 79.3 mm, TL 152.3 mm. HL 13.1 mm, with relatively long snout (HL/HW 65.1%). Additional measurements are presented in Table 2. Ear opening small, without anterior lobes. Rostral visible from above. Small nostrils set posteriorly so that postnasal effectively borders nostril. Supranasals without contact. Frontonasal wider than long, in contact with loreal scale. Prefrontals pentagonal, separated from one another, each in contact with the following head shields: frontonasal, loreal, first and second supraocular, second supraciliary and frontal. Two loreals. Frontal longer than the distance between anterior tip of frontal and tip of snout. Frontal in contact with three supraoculars on each side. Two frontoparietals, in contact with each other and the frontal, third and fourth supraoculars, parietal and interparietal. Frontoparietal plus interparietal length greater than frontal length. Interparietal twice as long as wide, with a visible parietal foramen. Parietals of same length as frontoparietals. Parietals not in contact with one another. Five supraciliaries, second largest. Seven supralabials, fifth being subocular. Six infralabials. Postmental bordering seven scales. Transparent scale present in lower eyelid, as is usual for Trachylepis . Tympanum visible, at same level as mouth. Dorsal scales each with three smooth keels, sometimes very indistinct. Ventral scales smooth. MSR 28, SAD 52, SAV 58. Limbs with five digits; scales on soles of hands and feet smooth. Relative length of fingers IV>III>II>V>I, relative length of toes IV>III>V>II>I. Finger-IV lamellae 13, Toe-IV lamellae 17. Color in life is homogenous light greenish-brown on the entire dorsum; head, neck, legs and tail uniformly light grey-brown. No visible spots, markings or dorsolateral stripes. Gular region white, remaining ventral areas yellowish, except the brown palmar regions of hand and feet. In preservative, background color of flanks and upper side of head, neck, dorsum, legs and tail homogenously brown, with some white speckles running from the labials through the anterior half of the tail. Above the labials the head is uniformly brown. Eyelids dark-brown. Ventral surfaces uniformly whitish with some scattered dark speckles near the flanks and under the tail.

Variation. Variation in measurements and scalation of the paratypes of Trachylepis raymondlaurenti sp. nov. are reported in Table 2. Head scalation similar to holotype in all paratypes except for prefrontals, which vary considerably; in RBINS 2 691 and RBINS 2695 the prefrontals are separated by an additional median scale, and in RBINS 2693 they are separated. Coloration of paratypes agrees entirely with that of holotype. Hatchlings have a reddish tail and hind legs ( Fig. 7 ).

Comparison with other species. Trachylepis raymondlaurenti sp. nov. differs from all congeners, with the exception of T. megalura and T. boulengeri , in being a slender skink with a well-marked neck, a very long tail (TL generally more than twice the SVL), and a low number of midbody scale rows (24–28) in comparison with the majority of Trachylepis species ( Broadley 2000). Trachylepis raymondlaurenti is readily distinguishable from T. megalura by its coloration and scalation. Trachylepis megalura is characterized by a striped pattern with a number of fine dorsal longitudinal black or white stripes (grey-brown, light orange-brown or golden or red-brown) including a very characteristic prominent white stripe on the flanks, bordered above by a black stripe running from the upper lip along the entire body onto the tail, while the new species is characterized by the lack of the lateral stripe on the flanks, being homogeneously greyish-brown dorsally with scattered dark speckles. In terms of scalation, the supranasals and prefrontals are never in contact in T. raymondlaurenti sp. nov., while in T. megalura they are both in contact. Trachylepis boulengeri shares more morphological similarities with the new species than with T. megalura . Both Trachylepis boulengeri and T. raymondlaurenti have a uniform grey-brown background, sometimes with a few scattered dark flecks, but T. boulengeri also exhibits a black streak from below the eye to the ear opening, which is not visible in T. raymondlaurenti . In both taxa the supranasals and prefrontals are without contact, although T. boulengeri frequently has only one pretemporal ( Broadley 2000), whereas T. raymondlaurenti has two. Trachylepis boulengeri has five to 11 keels per dorsal scale, whereas T. raymondlaurenti and T. megalura have only three weak keels, sometimes nearly indistinct.

Distribution. Trachylepis raymondlaurenti sp. nov. appears to be restricted to the southeastern DRC in the Katanga Region, and to northern Angola, with records for Malanje and Lunda-Norte provinces. The species potentially occurs in the neighboring provinces of Bié, Lunda-Sul and Moxico in Angola, and in northern parts of Zambia.

Habitat and Natural History notes. The holotype was found while it was basking under a shrub of Cryptosepalum maraviense Oliv. (Fabaceae) in a Miombo woodland habitat ( Fig. 8 ). Dissection revealed ten welldeveloped fetuses in the holotype ( Fig. 7 ), indicating that the young of this diurnal, viviparous species are likely born in late September or October. The fetuses, and presumably neonates, have bright reddish-orange tails that are proportionally shorter than in the adults. The relative length changes in tail length during ontogeny (and presumably also does so in T. megalura ), explain why the holotype of Eumeces massaianus , a probable subadult, has a proportionally shorter tail than the types of Euprepes megalurus , a fact which contributed to its early recognition as a distinct taxon.

Etymology. The species is named after Raymond F. Laurent (1917–2005), Belgian herpetologist who specialized in African amphibians and reptiles and contributed significantly to current knowledge of the Angolan and Congolese herpetofaunas. We propose the English name "Laurent’s Long Tailed Skink", the Portuguese name "Lagartixa de Cauda Longa de Laurent", and the French name "Scinque à longue queue de Laurent".

Figures

FIGURE 4. Distribution map of Trachylepis raymondlaurenti sp. nov. (blue squares) and T. megalura (yellow dots) in sub- Saharan Africa. For distributional data see Appendices I and II.

FIGURE 5. Preserved holotype of Trachylepis raymondlaurenti sp. nov. (CAS 258401). Photo by Luis M. P. Ceríaco.

FIGURE 6. Holotype of Trachylepis raymondlaurenti sp. nov. (CAS 258401) from Cangandala National Park, Angola in life. Photo by Luis M. P. Ceríaco.

FIGURE 7. General view of five out of the ten fetuses found in the reproductive tract of the holotype of Trachylepis raymondlaurenti sp. nov. Photos by Luis M. P. Ceríaco.

FIGURE 8. A: General view of the Miombo woodland habitat in the Giant Sable Sanctuary area in the Cangandala National Park where the holotype was collected. B: Cryptosepalum maraviense Oliv. shrub under which the holotype was found basking. Photos by Luis M. P. Ceríaco.