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Incompleteness of the fossil record has confounded attempts to establish the role of the end-Cretaceous bolide impact in the Late Cretaceous mass extinctions. Statistical analysis of latest Cretaceous outer-shelf macrofossils from western European Tethys reveals (i) a major extinction at or near the Cretaceous-Tertiary (K-T) boundary, probably caused by the impact, (ii) either a faunal abundance change or an extinction of up to nine ammonite species associated with a regression event shortly before the boundary, (iii) gradual extinction of most inoceramid bivalves well before the K-T boundary, and (iv) background extinction of approximately six ammonites throughout the latest Cretaceous., The end Cretaceous is marked by the extinction of 70% of species worldwide (1), which apparently coincided with the large bolide impact that created the 180-to 300-km-wide Chicxulub impact structure [...]

Analyses of recent data show that Floridian molluscan diversity declined markedly during the Pliocene-Pleistocene mass extinction. This decline in diversity was seen at all trophic levels, indicating a complete collapse of the ecosystem. These findings contradict the notion that there was a species diversity stasis throughout the Pliocene-Pleistocene and that the diversity of Pliocene Florida was equivalent to that of Recent Florida. The mass extinction was a two-staged, sequential event. A similar two-staged mass extinction occurred in the Miocene, indicating that two ecological catastrophes in quick geological succession may have produced this mass extinction as well., Studies of tropical western Atlantic Pliocene (Plio)-Pleistocene molluscan mass extinctions (1-8) have resulted in two conflicting conclusions. The main data soure used to arrive at these antitheses was the rich [...]

Some 425 million years ago, a heavily armored, wormlike mollusk died on the deep sea floor and was buried in volcanic ash. Now, using a novel technique, a team of [...]