Bivalve Mollusks as Hosts in the Fossil Record

Parasites are ubiquitous in modern ecosystems, occupy one of the most successful life modes, promote ecosystem stability, and, despite their typically diminutive size and lack of a mineralized skeleton, are commonly identifed in the fossil record. Bivalve mollusks have occupied marine aquatic environments since the Cambrian, comprise an excellent fossil record, and often preserve traces of interactions with their parasites. Here we review parasite-host interactions of living bivalves and the record of parasitism of bivalves that reaches as far back as the Silurian. Escalation in parasite-host bivalve interactions seems to have occurred in both the middle Paleozoic and the late Mesozoic to Cenozoic, similar to trends documented in other antagonistic interactions.