EFFECT OF EXTINCTION ON DUROPHAGY: A CASE STUDY FROM THE NEOGENE OF FLORIDA

Extinction, an important agent in macroevolution, has been predicted to destabilize or even reverse trends in predator-prey dynamics by eliminating some of the specialized predators and prey with energetically costly defenses. Temporal changes in traces of unsuccessful shell-breaking predatory attacks on Varicorbula sp. record change in site preference by durophagous predators before and after a regional Plio-Pleistocene extinction in Florida. Before this event, durophagous predators attacked both the ventral and posterior part of the prey shell in similar frequency (p=0.886), whereas after the crisis, predation was mostly concentrated at the ventral portion (p<0.001). This extinction event therefore appears to have reduced the collective prey handling diversity among surviving predators and demonstrates mechanistically how extinctions can disrupt selection regimes and influence subsequent evolution.