Oligotrophic oceans and minimalist organisms: collapse of the Maastrichtian marine ecosystem and Paleocene recovery in the Cretaceous-Tertiary sequence of New Jersey

Abstract

The inner Atlantic Coastal Plain of New Jersey reveals exposures of fossiliferous Maastrichtian and Danian deposits. Recent fossil discoveries in this interval are here reported, and placed in the context of Cretaceous/Tertiary (K/T) faunal changes. The exposure at the Inversand Pit at Sewell (New Jersey) is the last active marl mine in the region, and stands as an important reference section for the many significant discoveries of vertebrate fossils produced by the marl mining industry at its zenith. Changes in planktonic populations across the K/T boundary are related to Maastrichtian/Danian marine ecosystem community reorganisation, by demonstrating changes in abundance of dominant marine invertebrates in successive fossil assemblages. Marine invertebrates with non-planktotrophic larval stages were briefly the commonest fossils preserved in the Danian sediments of this region. Late surviving examples of Cretaceous fauna now restricted to the Indo-Pacific region may imply biogeographic changes linked to the K/T mass extinction event.