First occurrence of Psammophis (Serpentes) from Europe witnesses another Messinian herpetofaunal dispersal from Africa – biogeographic implications and a discussion of the vertebral morphology of psammophiid snakes

Abstract

We here describe abundant new snake material from the late Miocene (MN 13) of Salobreña, Spain. Vertebral morphology suggests a referral of the specimens to the extant psammophiid Psammophis, documenting the first occurrence of this genus in Europe. The diversity and disparity across the vertebral morphology of different psammophiid genera are discussed. We identify vertebral features that could diagnose Psammophis and therefore enable the recognition of the genus in the fossil record. A comparison of the new Spanish form with other taxa is conducted. We provide a detailed review of the psammophiid fossil record. Material previously described from the middle Miocene of Beni Mellal, Morocco is here tentatively referred to as ?Psammophis sp., an action that renders that occurrence as the oldest (probable) record of the genus and Psammophiidae as a whole, providing thus a potential calibration point. On the other hand, Eastern European Pliocene material that had been previously supposedly referred to Psammophis is here discarded as being rather fragmentary, not affording any more precise determination. The two psammophiid genera Psammophis and Malpolon appear almost simultaneously in the European fossil record (MN 13), with the former achieving only a short‐lived and apparently geographically limited distribution in the continent, while the latter still exists in its modern herpetofauna. We assess biogeographic implications of the new find, suggesting a direct dispersal event from northwestern Africa to the Iberian Peninsula during the late Miocene, facilitated by the Messinian Salinity Crisis.

A study on the vertebral column of the dice snake Natrix tessellata (Serpentes, Natricidae) from Denizli (western Anatolia, Turkey)

“…In the Vipera ammodytes and V. aspis fossils, the zygosphene possesses three distinct lobes, and the pre‐zygapophyseal processes are extremely short (Szyndlar, 1991). In the dorsal view of the trunk vertebra of Psammophis odysseus , the zygosphene possesses two distinct lateral lobes and a median lobe (Georgalis & Szyndlar, 2022). Loréal et al (2020) reported that in the trunk vertebrae of Colubrinae fossils, the zygosphenes appeared thin and exhibited a convex shape when viewed anteriorly.…”

“…According to Szyndlar (1984), the classification of trunk vertebrae in the genus Natrix is based on a specific combination of characteristics, including elongated shape, sigmoid hypapophysis, well‐developed and rounded pre‐zygapophyseal processes, horizontally positioned pre‐zygapophyses, vaulted neural arches, and prominent neural spines. Georgalis and Szyndlar (2022) reported that the mid and posterior trunk vertebrae of Psammophis sp. lack hypapophyses.…”

Novel phylogenomic inference and ‘Out of Asia’ biogeography of cobras, coral snakes, and their allies

“…Kurniawan et al [148] hypothesized that the earlier of these Psammophis immigration events occurred by dispersal across the Gomphotherium land bridge, and our biogeographic and divergence time results were consistent with this hypothesis (figure 4). The importance of Psammophis fossils from the Late Miocene of Spain [150]-where the genus does not presently occur-in understanding when and how ancestors of extant Psammophis lineages arrived in Asia is not clear.…”

Novel phylogenomic inference and ‘Out of Asia’ biogeography of cobras, coral snakes and their allies

“…Kurniawan et al [154] hypothesized that the earlier of these Psammophis immigration events occurred by dispersal across the Gomphotherium land bridge, and our biogeographic and divergence time results were consistent with this hypothesis (figure 4). The importance of Psammophis fossils from the Late Miocene of Spain [156]-where the genus does not presently occur-in understanding when and how ancestors of extant Psammophis lineages arrived in Asia is not clear.…”