Echinoid Associated Traces (EAT)

Predation traces found on fossilized prey remains can be used to quantify
the evolutionary history of biotic interactions. Fossil mollusk shells
bearing these types of traces provided key evidence for the rise of
predation during the Mesozoic Marine Revolution (MMR), an event which is
thought to have reorganized global marine ecosystems. However, predation
pressure on prey groups other than mollusks has not been explored
adequately. Consequently, the ubiquity, tempo, and synchronicity of the
MMR cannot be thoroughly assessed. Here, we expand the evolutionary record
of biotic interactions by compiling and analyzing a new
comprehensively-collected database on drilling predation in Meso-Cenozoic
echinoids. Trends in drilling frequency reveal an Eocene rise in drilling
predation that postdated echinoid infaunalization and the rise in
mollusk-targeted drilling (an iconic MMR event) by ~100 million years. The
temporal lag between echinoid infaunalization and the rise in drilling
frequencies suggests that the Eocene upsurge in predation did not elicit a
co-evolutionary or escalatory response. This is consistent with rarity of
fossil samples that record high frequency of drilling predation and
scarcity of fossil prey recording failed predation events. These results
suggest that predation intensification associated with the MMR was
asynchronous across marine invertebrate taxa and represented a long and
complex process that consisted of multiple uncoordinated steps likely with
variable co-evolutionary responses.