The Early Pleistocene herpetofauna of Rivoli Veronese (Northern Italy) as evidence for humid and forested glacial phases in the Gelasian of Southern Alps

Among the Early Pleistocene Italian fossil herpetofaunas, Rivoli Veronese is remarkable in having yielded the youngest known allocaudates, represented by Albanerpeton pannonicum, together with remains of other amphibians and reptiles. The assemblage includes at least 15 other taxa, including two caudates (Speleomantes sp., Ichthyosaura alpestris), four anurans (Bombina sp., Bufo bufo, Hyla gr. H. arborea, Rana sp.), five lizards (Lacerta gr. L. viridis, cf. Zootoca vivipara, a third, small-sized lacertid, Anguis gr. A. fragilis, cf. Pseudopus sp.) and four snakes (Coronella sp., Zamenis longissimus, Natrix sp., Vipera gr. V. aspis). The finding of Speleomantes is particularly interesting as it is one of only a handful of fossil occurrences of this genus, being only the second one outside of its extant range. Excluding the extinct Albanerpeton and Speleomantes, which has a very narrow environmental range, the remainder of the assemblage suggests a Mean Annual Temperature rather similar or slightly colder than the present one in Rivoli Veronese (11.6 °C versus 12.4 °C), with much higher Mean Annual Precipitation (1322 mm versus 834 mm). The palaeoenvironment would have included either permanent or temporary water bodies, located in a forested area. More open landscapes might have also been present in the local vicinity. The palaeoherpetofauna of Rivoli Veronese supports the hypothesis of Albanerpeton favouring a moist environment, and confirms the presence of a humid forested landscape on the northern side of the Po Plain during the cold phases of the Gelasian, as already suggested by the pollen record for its southern margin.