291-10 Calamari through time: Assessing the relationships between biotic interactions, global change, and cephalopod biodiversity

Session: Cephalopods Through Time: Insights into Evolution, Ecology, and Environmental Reconstruction

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Cephalopods have existed in Earth’s oceans since the Cambrian period, and during that time, they have played the roles of predator, prey, and host within their communities. The extent to which these biotic interactions were related to cephalopod macroevolution remains unresolved. In this study, we examine literature sourced data on predation and parasitism traces preserved on cephalopod shells, compile abiotic environmental proxy data from the published literature, and calculate mean sampled genus diversity along with gap-filler origination and extinction rates from the Paleobiology Database to disentangle these threads using Generalized Additive Models at stage temporal resolution. Mean sampled diversity increases linearly with continental fragmentation, increases with moderate parasitism, slightly increases with moderate to high predation, and slightly decreases with increasing CO₂. Origination rates increase at moderate equatorial temperatures (but decrease when they are high), decrease non-linearly with increasing latitudinal temperature gradient, and decrease with a moderate amount of predation. Extinction rates increase linearly with CO₂, decrease with large latitudinal temperature gradients (>40˚C), increase with moderate to high amounts of parasitism, and slightly decrease with moderate to high amounts of predation. An analysis of predation frequency and parasitism prevalence (from samples with n >= 10) revealed that elevated pressure from these antagonistic interactions is associated with elevated CO₂, lower local sea surface temperatures, increased origination rates, and decreased extinction rates. These results highlight the complex nature of the macroevolution of this diverse group of predators that is shaped by the physiological constraints of temperature and CO₂, antagonistic biotic interactions within complex trophic webs, as well as plate tectonics.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10360

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