The biogeography of Elaphe sauromates (Pallas, 1814), with a description of a new rat snake species

A new, rare, small-ranged, and endangered mountain snake of the genus Elaphe from the Southern Levant

The genus Elaphe Fitzinger, 1833 includes 17 species of charismatic, large-sized, non-venomous, Eurasian snakes. In the Western Palearctic, the genus is represented by three species from the Elaphe quatuorlineata group ranging from the Apennine peninsula to Central Asia. The southernmost population of this group is distributed in the mountains of the Southern Levant, with more than 400 km gap to other Elaphe populations. This population has been known to science for only 50 years and is virtually unstudied due to its extreme rarity. We studied these snakes' morphological and genetic variation from the three countries where they are known to occur, i.e., Israel (Hermon, the Israeli-controlled Golan Heights), Lebanon, and Syria. We used nine mitochondrial and nuclear genes, complete mitogenome sequences, and a comprehensive morphological examination including published data, our own field observations, and museum specimens, to study its relationship to other species in the group. The three currently recognized species of the group (E. quatuorlineata, E. sauromates, E. urartica), and the Levant population, form four deeply divergent, strongly supported clades. Three of these clades correspond to the abovementioned species while the Southern Levant clade, which is genetically and morphologically distinct from all named congeners, is described here as a new species, Elaphe druzei sp. nov. The basal divergence of this group is estimated to be the Late Miocene with subsequent radiation from 5.1 to 3.9 Mya. The revealed biogeography of the E. quatuorlineata group supports the importance of the Levant as a major center of endemism and diversity of biota in Eurasia. The new species is large-sized and is one of the rarest snakes in the Western Palearctic. Because of its small mountain distribution range, in an area affected by land use and climate change, the new Elaphe urgently needs strict protection. Despite political issues, we hope this will be based on the cooperation of all countries where the new species occurs.

A sheep in wolf's clothing: Elaphe xiphodonta sp. nov. (Squamata, Colubridae) and its possible mimicry to Protobothrops jerdonii

Based on combined morphological and osteological characters and molecular phylogenetics, we describe a new species of the genus Elaphe that was discovered from the south slope of the Qinling Mountains, Shaanxi, China, namely Elaphe xiphodonta sp. nov. It is distinguished from the other congeners by a combination of the following characters: dorsal scales in 21-21-17 rows, the medial 11 rows keeled; 202-204 ventral scales, 67-68 subcaudals; two preoculars (including one subpreocular); two postoculars; two anterior temporals, three posterior temporals; reduced numbers of maxillary teeth (9+2) and dentary teeth (12); sharp cutting edges on the posterior or posterolateral surface of the rear maxillary teeth and dentary teeth; dorsal head yellow, three distinct markings on the head and neck; a distinct black labial spot present in supralabials; dorsum yellow, 46-49 complete (or incomplete) large black-edged reddish brown blotches on the body and 12-19 on the tail, two rows of smaller blotches on each ventrolateral side; ventral scales yellow with mottled irregular black blotches, a few irregular small red spots dispersed on the middle of the ventral. Based on molecular phylogenetic analyses, the new species forms the sister taxon to E. zoigeensis. The discovery of this new species increases the number of the recognized species in the genus Elaphe to 17.

A new species of Gonyosoma Wagler, 1828 (Serpentes, Colubridae), previously confused with G. prasinum (Blyth, 1854)

A new species of the genus Gonyosoma Wagler is described from Yunnan Province, China. The new species closely resembles G. prasinum (Blyth), but it is differentiated from the latter species by the following characters: precloacal plate divided, iris blue and inside of mouth greyish-white in life. Based on phylogenetic analyses of mitochondrial cytochrome b sequence data, the new species is recovered as the sister species to G. prasinum by Bayesian Inference and Maximum Likelihood analyses. The uncorrected pairwise distance between the new species and other species of the genus Gonyosoma ranged from 11.78% to 17.07% calculated using the mitochondrial cytochrome b sequence. This discovery increases the number of Gonyosoma species to seven.

Common patterns in the molecular phylogeography of western palearctic birds: a comprehensive review

A plethora of studies have offered crucial insights in the phylogeographic status of Western Palearctic bird species. However, an overview integrating all this information and analyzing the combined results is still missing. In this study, we compiled all published peer-reviewed and grey literature available on the phylogeography of Western Palearctic bird species. Our literature review indicates a total number of 198 studies, with the overwhelming majority published as journal articles (n = 186). In total, these literature items offer information on 145 bird species. 85 of these species are characterized by low genetic differentiation, 46 species indicate genetic variation but no geographic structuring i.e. panmixia, while 14 species show geographically distinct lineages and haplotypes. Majority of bird species inhabiting the Western Palearctic display genetic admixture. The glaciation cycles in the past few million years were pivotal factors in shaping this situation: during warm periods many species expanded their distribution range to the north over wide areas of Eurasia; whereas, during ice ages most areas were no longer suitable and species retreated to refugia, where lineages mixed.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10336-021-01893-x.

The first comprehensive data on the distribution of reptiles within the Southern Bug eco-corridor, Ukraine

This study provides distribution data for 12 species of reptiles in the Southern Bug eco-corridor located within the steppe zone, Mykolaiv Oblast (province), Ukraine. We compiled 935 records from published literature (324), from public databases (68), and from 12 field surveys we made in 2016–2020 (543). All records were mapped on to a grid of 10×10 km, representing the 294 cells of the studied area. We present new distributional data for Podarcis tauricus. For all the other species, our records add new localities that fall within areas where these reptiles were previously reported. Species richness and Shannon’s H’ index show that herpetofauna diversity was higher in the areas along the Southern Bug River. The maximum number of records within a single cell was 118 (for 10 species) in this oblast. Also the high number of identified reptile chorotypes (nine) within the Mykolaiv Oblast revealed that southern Ukraine is an important zoogeographical territory in Europe. These data provide the basis for future biogeographical and ecological studies and conservation priorities.

Morphological and genetic differentiation in the anguid lizard Pseudopus apodus supports the existence of an endemic subspecies in the Levant

The Levant represents one of the most important reptile diversity hotspots and centers of endemism in the Western Palearctic. The region harbored numerous taxa in glacial refugia during the Pleistocene climatic oscillations. Due to the hostile arid conditions in the warmer periods they were not always able to spread or come into contact with populations from more distant regions. One large and conspicuous member of the Levantine herpetofauna is the legless anguid lizardPseudopus apodus. This species is distributed from the Balkans to Central Asia with a portion of its range running along the eastern Mediterranean coast. Mitochondrial and nuclear DNA sequences, microsatellite genotypes, and morphology show that populations in this region differ from the two named subspecies and presumably had a long independent evolutionary history during the Quaternary. Here we describe the Levantine population as a new subspecies and present biogeographic scenarios for its origin and diversification. The new subspecies is genetically highly diverse, and it forms a sister lineage toPseudopusfrom the remaining parts of the range according to mtDNA. It is the largest-bodied of the three subspecies, but occupies the smallest range.

Quaternary range dynamics and taxonomy of the Mediterranean collared dwarf racer, Platyceps collaris (Squamata: Colubridae)

The geological and geographical settings of the Eastern Mediterranean have resulted in complex patterns of intraspecific diversifications and phylogeographical histories that can be observed in squamates. In this study, we examined genetic differentiation of the Collared dwarf racer (Platyceps collaris) using a multilocus genetic dataset with a sampling that covered the entire range of the species. We developed distribution models in current and past climatic conditions to assess the dynamics of the species distribution through time. We sequenced a fragment of the cytochrome b mitochondrial gene of the holotype and eight paratypes of Coluber rubriceps thracius, which is considered a synonym of Platyceps collaris. Our results show that there are two distinct clades within P. collaris, one occupying the Balkans and western and southern Anatolia (termed the Balkan–Anatolian clade), the other in the Levant (termed the Levantine clade). All type specimens of C. r. thracius are genetically identical and cluster within the Balkan–Anatolian clade. Distribution models indicate the presence of two refugia during climatically challenging periods. One was in western Anatolia and served as a source for the colonization of the Balkans and southern Anatolia, and the other was in the northern Levant, from where P. collaris dispersed further south. According to our results, we revise the subspecific taxonomy of P. collaris.

Multilocus species-delimitation in the Xerotyphlops vermicularis (Reptilia: Typhlopidae) species complex

Scolecophidia (worm snakes) are a vertebrate group with high ecomorphological conservatism due to their burrowing lifestyle. The Eurasian or Greek blindsnake Xerotyphlops vermicularis is their only European representative, a species-complex with an old diversification history. However, its systematics and taxonomy has remained untouched. Here, we extend previous work that relied heavily on mitochondrial markers, following a multi-locus approach and applying several species-delimitation methods, including a Bayesian coalescence-based approach (STACEY). Four "species" delimitation analyses based on the mtDNA (ABGD, bGMYC, mPTP, parsimony networks) returned 14, 11, 9 and 10 clusters, respectively. By mitotyping twice as many specimens as before, we have a complete picture of each cluster's distribution. With the exception of the highly-divergent Levantine lineage, the three independent nuclear markers did not help with phylogenetic resolution, as demonstrated in haplotype networks, concatenated and species-trees, a result of incomplete lineage sorting. The prevailing model from the coalescence-based species-delimitation identified two species: the lineage from the Levant and all others. We formally recognize them as distinct species and resurrect Xerotyphlops syriacus (Jan, 1864) to include the Levantine blindsnakes. Finally, X. vermicularis and X. syriacus may represent species-complexes themselves, since they include high levels of cryptic diversity.