Global climate model comparisons of niche evolution in turritelline gastropods across the Cretaceous–Paleogene mass extinction

Paleo-ecological niche modeling (paleoENM) estimates the niches and distributions of extinct species using fossil paleo-coordinates and local environmental data. While general circulation models (GCMs) have been used to estimate climate conditions in deep time, primarily for terrestrial vertebrates, variations in paleo-elevation models used in GCM construction can influence paleoENM outcomes. This study (1) examines the impact of the Cretaceous–Paleogene (K-Pg) mass extinction on the niche dimensions of the marine invertebrate group Turritellinae (Cerithoidea: Turritellidae) and (2) compares two paleo-elevation models’ effects on GCM-based species’ distribution predictions. Fossil occurrence data from the Maastrichtian and Danian periods were collected from the Paleobiology Database (PBDB), museum collections, and published literature. Environmental data were extracted from HadCM3L GCM simulations using Scotese- and Getech-based paleogeographic and pCO2 boundary conditions. We estimated the niche dimensions of turritellines using maximum entropy (MaxEnt) and performed ordination analysis using kernel density estimation. MaxEnt model metrics showed that the Getech-based GCM outperformed the Scotese-based GCM. Geographic projections revealed minor differences in suitable habitat between the Maastrichtian and Danian in the Getech-based GCM, but overinflated predictions in the Scotese-based GCM. Niche overlap between the Maastrichtian and Danian was high, with both GCMs supporting niche similarity and equivalency. Our results suggest that differences in elevation model boundary conditions affected predicted distribution and niche patterns. This study offers a novel approach to understanding ecological persistence in invertebrates after mass extinction events, examines the robustness of GCM boundary conditions in paleoENM studies, and provides a framework for future paleoecological research on fossil invertebrates.