The taxonomic status of the kukri snake Oligodon arenarius Vassilieva, 2015 with a redescription of Oligodon macrurus (Angel, 1927) (Squamata, Serpentes, Colubridae)

We investigated the taxonomic status of the recently described kukri snake Oligodon arenarius Vassilieva, 2015 and the morphologically similar Oligodon macrurus (Angel, 1927), two species endemic to the southern coast of Vietnam. Based on phylogenetic analyses using three mitochondrial genes (12S–16S rRNA, cytochrome b), we recovered O. arenarius and O. macrurus in a clade within the O. cyclurus-taeniatus species group, agreeing with previous intrageneric classifications. Genetic distances between O. arenarius and O. macrurus are extremely low (less than 0.5% based on 12S–16S) and render O. arenarius paraphyletic. All preserved specimens of O. arenarius and O. macrurus convey little to no differences in color pattern, hemipenial morphology and osteological features; the latter of which is based on three dimensional micro computer tomography (µCT) scans of one specimen per species. Contrasting these results, univariate and multivariate analyses revealed significant differences in relative tail length, and the number of ventral and subcaudal scales between both species. Although the molecular and morphological datasets present conflicting results, integrating the evidence leads us to synonymize O. arenarius with O. macrurus. We provide a formal redescription of O. macrurus, designate a neotype specimen to avoid future taxonomic confusion, and provide the first detailed osteological description of this species. Oligodon macrurus sensu stricto is endemic to coastal dunefields and adjacent forest habitats in southern Vietnam, where ongoing human development, tourism and road mortality pose significant threats to its conservation. Consequently, we suggest that O. macrurus should be listed as “Vulnerable” based on the assessment criteria of the International Union for Conservation of Nature (IUCN)

The first Miocene fossils of Lacerta cf. trilineata (Squamata, Lacertidae) with a comparative study of the main cranial osteological differences in green lizards and their relatives.

We here describe the first fossil remains of a green lizard of the Lacerta group from the late Miocene (MN 13) of the Solnechnodolsk locality in southern European Russia. This region of Europe is crucial for our understanding of the paleobiogeography and evolution of these middle-sized lizards. Although this clade has a broad geographical distribution across the continent today, its presence in the fossil record has only rarely been reported. In contrast to that, the material described here is abundant, consists of a premaxilla, maxillae, frontals, parietals, jugals, quadrate, pterygoids, dentaries and vertebrae. The comparison of these elements to all extant green lizard species shows that these fossils are indistinguishable from Lacerta trilineata. Thus, they form the first potential evidence of the occurrence of this species in the Miocene. This may be also used as a potential calibration point for further studies. Together with other lizard fossils, Solnechnodolsk shows an interesting combination of survivors and the dawn of modern species. This locality provides important evidence for the transition of an archaic Miocene world to the modern diversity of lizards in Europe. In addition, this article represents a contribution to the knowledge of the comparative osteological anatomy of the selected cranial elements in lacertids. This study gives special emphasis to the green lizards, but new data are also presented for related taxa, e.g., Timon lepidus, Podarcis muralis or Zootoca vivipara. Although the green lizards include several cryptic species for which determination based on isolated osteological material would be expected to be difficult, our comparisons show several important morphological differences, although a high degree of variability is present

The taxonomic status of the kukri snake Oligodon arenarius Vassilieva, 2015 with a redescription of Oligodon macrurus (Angel, 1927) (Squamata, Serpentes, Colubridae)

We investigated the taxonomic status of the recently described kukri snake Oligodon arenarius Vassilieva, 2015 and the morphologically similar Oligodon macrurus (Angel, 1927), two species endemic to the southern coast of Vietnam. Based on phylogenetic analyses using three mitochondrial genes (12S–16S rRNA, cytochrome b), we recovered O. arenarius and O. macrurus in a clade within the O. cyclurus-taeniatus species group, agreeing with previous intrageneric classifications. Genetic distances between O. arenarius and O. macrurus are extremely low (less than 0.5% based on 12S–16S) and render O. arenarius paraphyletic. All preserved specimens of O. arenarius and O. macrurus convey little to no differences in color pattern, hemipenial morphology and osteological features; the latter of which is based on three dimensional micro computer tomography (µCT) scans of one specimen per species. Contrasting these results, univariate and multivariate analyses revealed significant differences in relative tail length, and the number of ventral and subcaudal scales between both species. Although the molecular and morphological datasets present conflicting results, integrating the evidence leads us to synonymize O. arenarius with O. macrurus. We provide a formal redescription of O. macrurus, designate a neotype specimen to avoid future taxonomic confusion, and provide the first detailed osteological description of this species. Oligodon macrurus sensu stricto is endemic to coastal dunefields and adjacent forest habitats in southern Vietnam, where ongoing human development, tourism and road mortality pose significant threats to its conservation. Consequently, we suggest that O. macrurus should be listed as "Vulnerable" based on the assessment criteria of the International Union for Conservation of Nature (IUCN)