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| Paikwaophis kruki Kok & Means, 2023 |
Abstract
Pantepui s.l. is a remote, biodiverse region of ~400 000 km2 containing at least five endemic reptile genera and a number of ancient vertebrate lineages. Here, we describe an additional endemic snake genus and species, Paikwaophis kruki gen. nov., sp. nov. (Dipsadidae: Xenodontinae), recently collected in the Pantepui cloud forest that sits at the base of the steep cliffs of Roraima-tepui and Wei-Assipu-tepui (table mountains of the Eastern Tepui Chain) in Guyana, South America. Multilocus molecular data strongly support Paikwaophis gen. nov. to be most closely related to Xenopholis Peters, 1869, although both genera are strikingly different morphologically. Osteological and other phenotypic data suggest that Paikwaophis is semi-fossorial; its diet includes minute lizards. Paikwaophis is currently the only known Pantepui endemic snake genus. The immature female holotype is the only known specimen.
Keywords: anatomy, BDNF nuDNA gene, c-mos nuDNA gene, cytb mtDNA gene, Guiana Shield, Guyana, 12S rRNA gene, 16S rRNA gene, ND4 mtDNA gene, osteology
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| Phylogenetic relationships of the family Dipsadidae inferred from a concatenated dataset of six genes (four mtDNA and two nuDNA genes; 3772 bp) using Bayesian inference. Statistical supports for both Bayesian and maximum likelihood (IQ-TREE) analyses are provided at nodes (see key, lower right inset). Photographs are by D.B.M. (Paikwaophis kruki) and courtesy of the Reptiles of Ecuador book project (Xenopholis scalaris). |
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| Three-dimensional model of the skull of the holotype of Paikwaophis kruki (RBINS 2734) based on μCT imagery. A, dorsal view. B, lateral view. C, ventral view. Abbreviations: bo, basioccipital; bs, basisphenoid; col, columella; cp, compound bone; cps, conchal process of septomaxilla; d, dentary; ecp, ectopterygoid; exo, exoccipital; f, frontal; mx, maxillary; na, nasal; occ, occipital; p, parietal; pal, palatine; pfr, prefrontal; pmx, premaxilla; po, postorbital; pro, prootic; psp, parasphenoid rostrum; pt, pterygoid; q, quadrate; smx, septomaxilla; so, supraoccipital; st, supratemporal; su, supraorbital; v, vomer. |
Family Dipsadidae Bonaparte, 1838
Subfamily Xenodontinae Cope, 1893
Paikwaophis gen. nov.
Type species: Paikwaophis kruki sp. nov.
Etymology: The generic name is derived from the river name ‘Paikwa’ (referring to the type locality) and the Greek ‘ophis’ (meaning snake).
Generic diagnosis: Paikwaophis can be differentiated from all other Xenodontinae (and Dipsadidae) by the combination of the following morphological characters: head poorly distinct from neck; body robust, slightly wider than high; tail short, ~13% of total length in female; snout short and blunt; rostral wider than high, visible from above; undivided nasal; paired internasals; paired prefrontals; subtriangular frontal; absence of loreal; presence of minute cephalic sensory pits; eye medium in size, with vertically oval pupil, iris dark reddish orange; single supraocular; one preocular, two postoculars; three rows of temporals; chinshields medium in size, anterior chinshields projecting frontolaterally; body scales rhomboid, smooth, lacking keels or apical pits, 17 dorsal scale rows without reduction; subcaudals paired; anal entire; aglyphous, presence of a diastema; low number of teeth: 7 prediastemal maxillary teeth, 2 enlarged postdiastemal maxillary teeth, 8 pterygoid teeth, 5 palatine teeth, 12 dentary teeth; neural spines smooth, ungrooved and not laterally expanded; 175 trunk vertebrae; absence of hypapophyses on posterior vertebrae; caudal vertebrae with distinct haemapophyses; lacrimal foramen large and vertically ovoid; and postorbital bone highly reduced, free from the frontal bone.
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| Holotype of Paikwaophis kruki (RBINS 2734). A, dorsal view in life (photograph by D.B.M.). B, dorsolateral view of anterior body in life (photograph by D.B.M.). C, ventral view in preservative (photograph by P.J.R.K.). |
Paikwaophis kruki gen. nov., sp. nov.
Etymology: The specific epithet ‘kruki’ is a noun in the genitive case, honouring Professor Andrzej Kruk (born 1971), the current Dean of the Faculty of Biology and Environmental Protection at the University of Łódź, Poland, for his friendship and his influential contribution in enhancing the quality of research at the University of Łódź.
Philippe J. R. Kok and D. Bruce Means. 2023. Hiding in the Mists: Molecular phylogenetic position and Description of A New Genus and Species of Snake (Dipsadidae: Xenodontinae) from the Remote Cloud Forest of the Lost World. Zoological Journal of the Linnean Society. zlad082. DOI: 10.1093/zoolinnean/zlad082
