Three species of Rhynchocalamus are currently recognized, R. satunini (Turkey eastwards to Iran), R. arabicus (Yemen and Oman), and R. melanocephalus (from the Sinai Peninsula northwards to Turkey). Tamar et al. (2016) recently completed a comprehensive study on all known Rhynchocalamus species in order to review the intra-generic phylogenetic relationships and historical biogeography of the genus and describe a fourth species from Israel.
The molecular results found Rhynchocalamus monophyletic, and last shared an ancestor with Lytorhynchus in Late Oligocene. The three recognized species of Rhynchocalamus comprise four independently lineages with the genus diverge during the Middle Miocene. They discovered R. melanocephalus is paraphyletic. A population from the Negev Mountain area in southern Israel is phylogenetically closer to R. arabicus from Oman than to the northern populations of the species from Israel, Syria and Turkey and they describe this population as the new species Rhynchocalamus dayanae.
Citations
Å mÃd, J; MartÃnez G, Gebhart J, Aznar J, Gállego J, Göçmen B, De Pous P, Tamar K & Carran-za S. 2015. Phylogeny of the genus Rhynchocalamus (Reptilia; Colubridae) with a first record from the Sultanate of Oman Zootaxa 4033 (3): 380–392.
Tamar K, Å mÃd J, Göçmen B, Meiri S, Carranza S. (2016) An integrative systematic revision and biogeography of Rhynchocalamus snakes (Reptilia, Colubridae) with a description of a new species from Israel. PeerJ 4:e2769 https://doi.org/10.7717/peerj.2769.





