A New Species Of New Guinea Worm-Eating Snake (Elapidae: Toxicocalamus Boulenger, 1896), With Comments On Postfrontal Bone Variation Based On Micro-Computed Tomography
Morphology and DNA sequences are used to describe a new species of New Guinea Worm-Eating Snake (Elapidae: Toxicocalanms Boulenger, 1896) from Papua New Guinea: Toxicocalamus goodenoughensis n. sp., endemic to Goodenough Island of the D'Entrecasteaux Archipelago. Toxicocalamus goodenoughensis morphologically most closely resembles T. pachysomus Kraus, 2009, but it differs by having undivided nasal scales completely surrounding nares (vs. divided), pale yellow markings on supralabials (vs. purple), a yellow nape band (vs. unbanded uniform nape), a dark gray-brown dorsum (vs. medium brown), dark brown mottling on yellow ventral scales, darkening toward cloaca (vs. uniform light brown), and >175 ventral scales. Phylogenetically, T. goodenoughensis is sister to another D'Entrecasteaux endemic, T. nigrescens Kraus, 2017. Coalescent-based species delimitation found the new species to be uniquely delimited from all other taxa (n = 13) in all combinations of parameters settings. Micro-computed tomography (mu CT) scanning revealed the presence of distinctive variation in postfrontal bone morphologies, with three morphotypes exhibited within the genus: directed forward, directed lateral/perpendicular to cranium, and absent. Toxicocalamus goodenoughensis was found to have a sickle-shaped and directed forward postfrontal bone. The directed forward morphotype was shared by T. loriae Glade 3 (sensu Strickland et al., 2016), T. mintoni, T. nigrescens, and T. pachysomus. Our work is the most comprehensive phylogenetic analysis of the genus and the first study using mu CT scanning for comparative morphology of Toxicocalamus. We also provide an updated dichotomous key for the genus.
Publication Source (Journal or Book title)
Journal Of Herpetology
Roberts, J. R., & Austin, C. C. (2020). A New Species Of New Guinea Worm-Eating Snake (Elapidae: Toxicocalamus Boulenger, 1896), With Comments On Postfrontal Bone Variation Based On Micro-Computed Tomography. Journal Of Herpetology, DEC (4), 446. https://doi.org/10.1670/20-043