ABSTRACT
Recent work on fossil decapod Crustacea has provided a sufficiently large data set to facilitate a synthesis of the effect of the proposed end-Cretaceous extinction event(s) on the group in the North Pacific Ocean, the Central Americas, and the Southern Hemisphere, as well as on the global occurrences of eight families that have been recently revised by the authors. Of the 38 Late Cretaceous decapod families known from the data set as defined herein, 79% survived into the Palaeogene and 66% are extant. Only three of the families that became extinct during the Late Cretaceous have confirmed Maastrichtian records, and one of those is last known from lower Maastrichtian occurrences. Seventy percent of the Late Cretaceous genera in the data set became extinct during the Late Cretaceous; however, only about one-third had last occurrences during the Maastrichtian. Because of the high level of survivorship of families, these extinctions were pseudoextinctions; species within these families must have survived across the boundary. Of the survivors, some appear to have been preadapted survivors, ecological generalists, or refugium taxa, and some were protected by inhabiting buffered habitats in high-latitude areas. It is important to note that these features also confer survivability whether or not a mass extinction event occurred, hence the reason that many of those lineages are extant. Decapods inhabiting high-latitude areas survived preferentially, but notably, many genera survived into the Palaeogene in the tropical and subtropical Americas, proximal to the Chicxulub impact. Broad geographic range also conferred significant survival success on decapod genera. The Cretaceous, as well as the Eocene and Miocene, was a time of rapid evolutionary radiation within the Decapoda. Gouldian contingency may have played as significant a role in the survivorship of some decapod lineages as mass extinction events in causing selective extinctions.
