Biogeodynamic Barrier: Lithospheric Delamination and Delayed Miocene Faunal Migration in the Anatolian Highland

Biogeodynamics research seeks to link lithospheric scale processes with surface ecosystem evolution. Western Anatolia-Aegean region provides a critical testing ground for this coupling, where mantle dynamics have driven dramatic topographic reversals. Tectonostratigraphic and geomorphic insights indicate that Western Anatolia maintained elevated landscapes prior to and through Early Miocene extension. These observations are inconsistent with simple rift-related thinning but support dynamic uplift driven by removal of dense lithospheric mantle. Here, we integrate geodynamic modeling with geological observations to reconstruct the region's paleoelevation and its control on intercontinental faunal connectivity.  Our results indicate that lithospheric delamination (slab peel-back) was the primary driver of Early Miocene topography. Numerical models show that slab peeling from beneath the crust and subsequent asthenospheric upwelling triggered a transient surface uplift of > 1 km and southward younging volcanism from İzmir-Ankara suture to the western Taurides. Supported by metamorphic constraints indicating crustal thickness consistent with elevations of 2–3 km, these results are in good agreement with the existence of a paleo-"Anatolian Highland" at ~20 Ma.  Crucially, this geodynamically sustained topography acted as a significant biogeographic barrier. Synthesizing our models with recent fossil record analyses, we suggest that high elevations delayed faunal migration between Eurasia and Afro-Arabia, severing connectivity despite the closure of the Neo-Tethys. The timing of increased biotic interchange in the Middle–Late Miocene coincides with evidence for topographic lowering linked to post-delamination driven by crustal stretching.  We conclude that the thermal and mechanical evolution of the Anatolian lithosphere exerted a first-order control on the timing of biotic exchange, highlighting the direct link between lithosphere dynamics and vertebrate evolution.