Paleobiogeography and historical biogeography of the non-marine caenogastropod family Melanopsidae

Abstract

We investigate the distributions of representatives of the family Melanopsidae (Gastropoda: Caenogastropoda: Cerithioidea) from the late Cretaceous to present-day. The present contribution discusses and partly revises former schemes of melanopsid dispersal during the Cenozoic, all of which were based on outdated stratigraphic and tectonic concepts as well as an incompletely considered fossil record. Conflating a comprehensive and stratigraphically well-constrained fossil record, modern paleogeographical reconstructions and contemporary climate data, our goal is to present a thorough model of melanopsid distribution and its changes over the Cenozoic as well as its paleogeographical and climatic constraints. The family Melanopsidae evolved about 90Ma ago in the late Turonian from brackish cerithioidean ancestors. Cretaceous and Paleogene species occur in marginal marine to brackish environments along the shores of the Tethys and Paratethys seas. The extant clades of Melanopsis likely derive from the evolution of freshwater Melanopsis on the Balkan Peninsula back in the late early Miocene. Up to the Pliocene, freshwater species spread toward southwestern and southeastern Europe and successively replaced brackish-water representatives, paralleling a general decline of latter systems during the late Cenozoic. The southwards expansion of Melanopsis and its simultaneous retreat from northern latitudes resulted in the disjunct distribution pattern observed today.The genus Holandriana first appeared in northern Italy in the late early Miocene. The genera Microcolpia and Esperiana both first occurred in the late Miocene and likely derive from brackish-water Melanopsis species native to peri-Paratethyan lakes. The present-day biogeographic isolation of the three latter genera and Melanopsis roots in the climatic deterioration and the disappearance of major lake systems in southeastern Europe. While thermophilous Melanopsis retreated to the warm, dry climates of the Mediterranean and Middle East, Holandriana, Microcolpia and Esperiana adapted to the seasonal, cold-temperate climate of southeastern and eastern Europe and some species became restricted to thermal springs.