Data from: Tracking host–parasite interactions through coastal change from southern Brazil: implications for the Quaternary fossil record

Supplementary Data consists of two files. Supplementary Data 1 contains the raw specimen-level dataset used in all analyses, including taxonomic identifications, shell dimensions (length and height), valve side, age class, coastal-sector assignment (accretional or erosional), and trematode infection metrics (presence or absence, pit counts, and within-shell sector coding). This file enables readers to examine and reuse the original observations that support estimates of richness, prevalence, intensity, and within-shell spatial patterns. Supplementary Data 2 provides the complete, annotated R script used to process the raw data and reproduce all statistical models, figures, and tables presented in the paper. Together, these files ensure that others can replicate or adapt every analytical step, from data wrangling to model fitting and visualization.