Monday, March 8, 2021

[Herpetology • 2021] Amphisbaena elbakyanae • A New Species of Amphisbaena (Squamata: Amphisbaenidae) from the Orinoquian Region of Colombia

Amphisbaena elbakyanae 
Torres-Ramírez, Angarita-Sierra & Vargas-Ramírez, 2021

In northern South America, amphisbaenians are rarely seen among the herpetofauna.Thus, general knowledge about them is very poor. During a herpetological survey in 2012 at Casanare, Colombia, we found two specimens of an unusual Amphisbaena. A third specimen sharing the same morphotype labeled Amphisbaena sp. from Vichada department was found deposided in an Colombian reptile collection. Based on morphological analyses together with phylogenetic analyses of 1029 base pairs of the mitochondrial DNA (mtDNA), we describe a new species of Amphisbaena that inhabits in the Orinoquian region of Colombia. The new species is part of a phylogenetic clade together with A. mertensii and A. cunhai (central-southern Brazil), exhibiting a great genetic distance (26.1–28.9%) between the newly identified lineage versus those taxa, and versus the sympatric taxa A. alba and A. fuliginosa. Morphologically, this new Amphisbaena can be distinguished from their congeners by characters combination of number of preocloacal pores, absence of malar scale, postgenial scales and body and caudal annuli counts. Amphisbaena gracilis is on morphology grounds the most similar species. However, the new species can be distinguished from it by having higher body annuli counts, angulus ories aliegned with the edges of the ocular scales and center of frontal scales, less number of large middorsal segments of the first and second body annulus, and rostral scale visible from above. The description of this new Amphisbaena species points out the urgent need to increase the knowledge of worm lizards in Colombia

Keywords: burrowing habits, cryptic species, fossorial, integrative taxonomy, mtDNA, worm lizard, South America

Figure 4. Color in life of Amphisbaena elbakyanae sp. nov.
(A) Holotype of A. elbakyanae sp. nov., recently euthanized (MLS 1901, male).
(B) Specimen in life of Aelbakyanae sp. nov. from paratype locality: Bojonawi Natural Reserve, Fundación Omacha, municipality of Puerto Carreño, Vichada Department, Colombia (N 6.097997222, W - 67.48321667; elevation 54 m. a.s.l.). Photo by Beiker Castañeda.

Figure 2. Holotype Amphisbaena elbakyanae sp. nov. in preservation (MLS 1901, male).
 (A) Doral view of the head; (B) Lateral view of the head; (C) Ventral view of the head; (D) Ventral view of the tail (tail is autotomized).

Figure 3. Comparison of the head scuttelation between the holotypes of Amphisbaena elbakyanae sp. nov. and A. gracilis.
(A, C, E) Dorsal, lateral and ventral view of the head of A. elbakyanae sp. nov. (B, D, F) Dorsal, lateral and ventral view of the head of A. gracilis. (G) Lateral view of the caudal scuttelation of A. elbakyanae sp. nov.
Scales: 1 = nasals, 2 = prefrontals, 3 = frontals, 4 = oculars, 5 = rostral, 6 = supralabials, 7 = posoclulars, 8 = temporals, 9 = parietals, 10 = middorsals segments of the body annulus, 11 = first, second and third body annulus, 12 = infralabials, 13 = mental, 14 = postmentals, 15 = postgenials, 16 = postmalars, 17 = precloacal annulus, 18 = cloacal annuli, 19 = postcloacal annulus, 20 = autotomus annulus, 21 = postclocal lip, 22 = precloacal lip.

Amphisbaena elbakyanae sp. nov.
Chresonymy: Amphisbaena sp. (ICN-TAS 700): Pedroza-Banda et al. (2014).
Generic placement: Amphisbaena elbakyanae sp. nov. belong to the genus Amphisbaena Linnaeus, 1758 (sensu Mertens 1925; Vanzolini 1951; Gans and Alexander 1962) by having the following characters: (1) Snout rounded, flattened or slightly convexed above; (2) upper head scales paired; (3) rostral scale short, subtriangular, ventrally expanded and posteriorly without contact with prefrontal scales; (4) nasal scales in broad contact; (5) six premaxillary teeth; (6) ten maxillary teeth.

Diagnosis: Amphisbaena elbakyanae sp. nov., can be distinguished from all its congeners by the following combination of characters: (1) three supralabial scales; (2) three infralabial scales; (3) second supralabial scale longer than first and third supralabial scales, contacting first and third supralabial, temporal, ocular and prefrontal scales; (4) angulus oris lies in transverse plane passing through the posterior edges of the ocular scales and the center of the frontal scales; (5) second infralabial scale in contact with postmental scales; (6) six premaxillar teeth; (7) ten maxillar teeth; (8) one temporal scale; (9) absence of malar scale; (10) a single postgenial scale row with four segments; (11) postmalar scale rows with six to seven segments; (12) first body annulus includes one large segment on each side lying immediately posterior to inner parietal scales, abutting onto posterolateral edge of the outer parietal scales; (13) middorsal segments of second and third body annulus non-enlarged; (14) 245–257 body annuli; (15) 13–15 dorsal segments per annulus at midbody; (16) 16–18 ventral segments per annulus at midbody; (17) four precloacal pores; (18) autotomy sites located on sixth to eighth caudal annuli, (19) 20–24 caudal annuli, (20) rostral scale visible from above, (21) dorsal and ventral surfaces homogeneusly dark brown or dark brown-reddish, (22), and small body size 211–237 mm (Fig. 3).

Etymology: We dedicate this species to the Kazakhstani scientist Alexandra Asanovna Elbakyan (Russian: Алекса́ндра Аса́новна Элбакя́н), creator of the web site Sci-Hub, for her colossal contributions for reducing the barriers in the way of science, as well as her reclamation that “everyone has the right to participate and share in scientific advancement and its benefits, freely and without economic constraints”.

Distribution and natural history: The known localities of Amphisbaena elbakyanae sp. nov., are distributed in the flooded savanna ecosystem of the Orocué and Ariporo River basin, as well as in the drained savanna ecosystem of the Bita River basin in the department of Vichada (Fig. 5). Amphisbaena elbakyanae sp. nov. seems to be highly associated with the leaf litter of the savanna flood forest dominated by moriche palm (Mauritia flexuosa), which are commonly known as “morichales” or “cananguchales” in Colombia (Fig. 6). The new species was found in sympatry with A. alba and A. fuliginosa.

Figure 6. Habitat of Amphisbaena elbakyanae sp. nov.
(A) Panoramic view of savanna flood forest dominated by moriche palm at the Bita River, Department of Vichada, Colombia. (B) Microhabitats inside of moriche palm’s forest. (C) Moriche palm (Mauritia flexuosa).

 Juan José Torres-Ramírez, Teddy Angarita-Sierra and Mario Vargas-Ramírez. 2021. A New Species of Amphisbaena (Squamata: Amphisbaenidae) from the Orinoquian Region of Colombia. Vertebrate Zoology. 71: 55-74. DOI: 10.3897/vertebrate-zoology.71.e59461