Mesozoic and Cenozoic squamates of Europe

TLDR: In the early Eocene, a big wave of dispersals reached Europe during a marked rise in temperature at the beginning of the Eocene (MP 7) as mentioned in this paper. But this wave did not strongly affect squamates in Europe.

Abstract: Squamates first appeared in Europe in the Middle Jurassic. They were lizards that already included some crown-group members. Faunas of the Late Jurassic and Early Cretaceous were more or less a continuation of the Middle Jurassic assemblage. The early Late Cretaceous was characterised by a peculiar fauna of marine pythonomorphs, while terrestrial forms were rare. In the subsequent levels of the Late Cretaceous, marine forms were mainly mosasaurids; terrestrial assemblages heralding modern ones began to take form during the Campanian–Maastrichtian. The Cretaceous–Tertiary event did not strongly affect squamates in Europe. After poor Paleocene faunas, a big wave of dispersals reached Europe during a marked rise in temperature at the beginning of the Eocene (MP 7). The Eocene fauna was rich, diverse and of tropical type. In western Europe, a sharp extinction event (‘Grande Coupure’) eliminated most squamates at the end of the Eocene, but its impact in central and eastern Europe is unknown. The Oligocene fauna was transitional between the ‘old’ Eocene and the modern Miocene faunas. By the late early Miocene (MN 3–MN 4), the fauna markedly changed when an important wave of dispersals entered Europe during a climatic optimum. From the late middle Miocene onward, the temperature has dropped. As a consequence, faunas became less rich and regionalisation occurred. Numerous extinctions and withdrawals took place during the late Pliocene and early Pleistocene, leaving an impoverished fauna in Europe.