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| [A-D] Tantilla palamala sp. nov. Esqueda, Rojas-Runjaic, Correa, Ortiz, Guerrero, Jiménez, Bazó, Moreno-Pérez, Aguilar & Urra, [E-F] Tantilla melanocephala (Linnaeus, 1758) in Esqueda, Rojas-Runjaic, Correa, Ortiz, Guerrero, Jiménez-Bolaños, Bazó, Moreno-Pérez, Aguilar et Urra, 2025. |
Abstract
The highest elevations of the Tropical Andes form an archipelago of sky islands, where herpetological diversity is actively evolving. In this study, we combined morphological and molecular data to discover and describe a new snake species of the colubrid genus Tantilla from the middle-upper basin of the Boconó River on the lacustrine slope of the Cordillera de Mérida. This species belongs to the Tantilla melanocephala phenotypic group. Our results align with the previously published data, indicating that Andean populations diverged from a lowland ancestral lineage originating from the Guiana Shield and northern Brazil during the Miocene (~8 million years ago [Myr]). Morphologically, the new species is distinguished from the other members of the genus by its three longitudinal black stripes, the presence of two pale spots on the parietals instead of a pale nuchal band, noncontacting prefrontal and supralabial scales, the first pair of infralabial scales typically separated (rarely in contact), 138–145 ventral scales in males, <60 subcaudal scales in males, 12 maxillary teeth with a moderate diastema and an anterior process on the maxillary bone, and a unilobed, unicalyculate, and noncapitated hemipenis. We discuss the validity of certain available names and the zoogeographic patterns of Tantilla in its northernmost Andean distribution. Furthermore, our study provides the first evidence suggesting that Tantilla species richness may be underestimated in the mountainous regions of northern South America, where allopatric speciation driven by topographic complexity and niche conservatism has likely played a crucial role in the phenotypic and genotypic divergence of centipede snake populations.
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| Tantilla palamala sp. nov. (a-d) Life photos of the holotype, MZUC 47710: (a) dorsal view of the body and head, where the dark dorsolateral line can be observed; (b) lateral view of the head, showing the extension of the light band over the snout and the white orbicular spot behind the eye. Paratype, MZUC 47714: dorsal view of the body and close-up of the head in lateral view (c). Paratype, MZUC 47713: lateral and ventral views of the specimen before preservation; note the pale lemon-yellow ventral coloration (d). Specimen referring to Tantilla melanocephala from Venezuela, MZUC 47717, dorsal view and close-up of the head (e, f). |
Tantilla palamala Esqueda, Rojas-Runjaic, Correa, Ortiz, Guerrero, Jiménez, Bazó, Moreno-Pérez, Aguilar & Urra sp. nov.
Definition: (1) 15–15–15 dorsal scales rows, smooth, and without apical pits; (2) eight dorsocaudal scales to the tenth subcaudal; (3) loreal scale is absent; (4) divided cloacal scale; (5) preocular scale is present; (6) rostral visible from above, lateral margins extended and slightly curved similar to gull wings, forming an open V with a >90° obtuse angle, without rostral medial projection and moderate cleft, and margins contacting the prenasal straight or slightly straight; (7) 7(3, 4)/7(3, 4) supralabials; (8) 6(4)/6(4) infralabials; (9) 138–145 ventral scales in males; (10) 53–58 subcaudal scales in males; (11) noncontact prefrontals-supralabial; (12) hexagonal front shield, longer than wide; (13) first infralabial pair ...
Etymology: The specific name is a derived adjective from the Latin words “palam,” meaning in the presence of, openly and “ala,” meaning wing [Brown, 1956] to refer to a visible character in relation to the lateral margins of the rostral in dorsal view, that resemble a gull’s wing, that is, open and forming a V with a >90° obtuse angle and where the internasals tend to be laterally contracted.
Luis Felipe Esqueda, Fernando J.M. Rojas-Runjaic, Claudio Correa, Juan Carlos Ortiz, Pablo Guerrero, Juan David Jiménez-Bolaños, Santos Bazó, Pablo Athenogoras Moreno-Pérez, Melanio Aguilar and Félix Urra. 2025. Morphological and Molecular Analyses of Mountain Centipede Snake (Serpentes: Tantilla) reveal A New Species from Venezuelan Andes. Academia Biology. 3(1):1-25. DOI: doi.org/10.20935/AcadBiol7534
