Ammonites went extinct with the dinosaurs, but the Nautiloids didn’t. Why? They look the same?? During the Cretaceous period, ammonites were dominant, diverse surface dwellers- and the lesser nautiloids tended towards deeper water to avoid competing with their dominant cousins. One of the effects of the asteroid impact that ended the Mesozoic was ocean acidification. Ammonites and their thin-shelled young bobbed around in the gentle sunlit currents of the time, so acid rains and extinction of planktons they relied on ate away their shells and starved them. Some ammonites survived as long as 100,000 years after the impact, but ultimately, their specialized surface dwelling lifestyles killed them. On the other hand, the nautiloids, inhabitants of deeper waters, had less reliance on planktons and felt a softer blow from acidification. Thus, they expanded and thrived, until our furry antagonists evolved in the Oligocene, around 30 million years ago. . . . #paleontology #palaeontology #fossils #fossil #geology #fossilhunting #fieldwork #paleontologist #geoscience #paleontologytiktok