Data from: Changes in Bivalve functional and assemblage ecology in response to environmental change in the Caribbean Neogene

We documented changes in the relative abundance of bivalve genera and
functional groups in the southwest Caribbean over the past 11 Myr to
determine their response to oceanographic changes associated with the
closure of the Central American Seaway ca. 3.5 Ma. Quantitative bulk
samples from 29 localities yielded 106,000 specimens in 145 genera. All
genera were assigned to functional groups based on diet, relationship to
the substrate, and mobility. Ordinations of assemblages based on
quantitative data for functional groups demonstrated strong shifts in
community structure, with a stark contrast between assemblages older than
5 Ma and those younger than 3.5 Ma. These changes are primarily due to an
increase in the abundance of attached epifaunal bivalves (e.g., Chama,
Arcopsis, and Barbatia) and a decrease in infaunal bivalves (e.g.,
Varicorbula and Caryocorbula). Taxa associated with seagrasses, including
deposit-feeding and chemosymbiotic bivalves (e.g., Lucina), also increased
in relative abundance compared to suspension feeders. The composition of
bivalve assemblages is correlated with the carbonate content of sediments
and the percentage of skeletal biomass that is coral. Our results strongly
support the hypothesis that increases in the extent of coral reefs and
Thalassia communities were important drivers of biologic turnover in
Neogene Caribbean benthic communities.