Global palaeobiogeographic distribution patterns of the Cenozoic pleurotomariid gastropods (Family: Pleurotomariidae Swainson, 1840)

The palaeobiogeographic distributions of the pleurotomariid gastropods (Family Pleurotomariidae) are investigated from Maastrichtian (Latest Cretaceous) to Holocene to understand the global distribution patterns of this gastropod group during the Cenozoic. Although the diversity of the pleurotomariids considerably declined during the Late Cretaceous, they survived the K-Pg mass extinction and thrived in the Cenozoic. The Tethyan group of localities hosted the greatest diversity and thus, can be considered the central hub for the pleurotomariid gastropods throughout the Paleogene. However, with the closure of the Tethyan seaway during the early Neogene, their abundance significantly dropped in the Mediterranean. In the present times, this group has entirely disappeared from the Mediterranean Sea. The distribution became bicentric from the Middle Miocene onwards with one cluster in the Caribbean group of localities and the other in the Western Pacific group of localities. Latitudinal distribution of the fossil pleurotomariids shows that during the end-Cretaceous and Paleocene these gastropods were mostly confined to the polar and temperate latitudinal zones. However, they become more abundant in the temperate latitudinal zone during the Eocene and gradually expanded their habitat towards the tropical latitudinal zone from the Pleistocene onwards. Thus, a typical unidirectional shift from higher to lower latitudes is observed during the Cenozoic revealing habitat tracking in pleurotomariid gastropods.