How did the closure of the Tethys Ocean impact global marine biodiversity?

The closure of the Tethys Ocean during the Miocene represents one of the most profound reorganisations of Earth’s surface systems in the Cenozoic. Once a vast marine corridor linking the Indo-Pacific with the Atlantic and Mediterranean, the progressive narrowing and final disappearance of the Tethys dramatically altered ocean circulation, climate, and the dispersal opportunities available to marine organisms. While the geological processes of closure are increasingly well understood, its ecological and biogeographic consequences for global biodiversity remain less clearly resolved.

This PhD project will investigate how the restriction and closure of the Tethys Seaway shaped global marine biodiversity patterns, with a particular focus on dispersal and diversification dynamics. The research will ask: (1) How did changing gateway geometries influence dispersal pathways and connectivity among marine provinces? (2) Did diversification events coincided with key phases of seaway restriction? (3) Did biodiversity hotspots shift in response to declining connectivity? (4) How did coral assemblages reorganise ecologically in response to declining dispersal opportunities and habitat fragmentation?

Synthesis of fossil occurrence records will track how marine biodiversity changed through space and time in response to the closure of the Tethys Ocean. Dispersal modelling using palaeogeographic reconstructions and ocean circulation simulations will quantify potential connectivity between regions. Macroevolutionary analyses will test for links between seaway restriction and diversification pulses. Ecological comparisons across the Indo-Pacific, Mediterranean, Paratethys, and Atlantic will reveal how communities reorganised under declining connectivity. This research will provide new insights into how large-scale earth system changes reshape marine biodiversity.