Future palaeontologists will detect current mammal latitudinal biodiversity gradient

Aim: Fossil data provide crucial insights into past biogeographic and macroecological patterns. However, geological, biological, and sampling biases can potentially compromise genuine biodiversity inferences. Here, we tested whether fossil biases may hinder the accurate retrieval of the Latitudinal Biodiversity Gradient (LBG).
Location: Global.
Time period: Contemporary.
Major taxa studied: Mammals.
Methods: We implemented a filtering process to current mammal distribution maps, simulating one geological, two biological, and three sampling sources of bias. Namely, distribution maps were downgraded to regions with sediments, species preservation was modulated by their range size and body size, and sampling was applied to locations with a fossil record. We applied the filters sequentially to mimic a process of progressive fossilisation, considering three preservation rates and removing up to 98.8% of the original species. We also applied filters independently to assess their individual ef..., All analyses were conducted using R version 4.2.2 (R Core Team, 2022), and a list of implemented packages can be found in Table S9.
Mammal distribution data
We obtained current species range maps from the International Union for Conservation of Nature website (IUCN; https://www.iucnredlist.org/resources/spatial-data-download). Terrestrial mammal data were downloaded on 24th January 2022 and freshwater (inland water) mammal data on 21st September 2022. Range shapefiles were loaded in R using the ‘rgdal’ package version 1.5-28 (Bivand, Keitt, & Rowlingson, 2021). We excluded polygons associated with distributional data of Delphinidae, Iniidae, Lipotidae, Phocidae, Phocoenidae, Platanistidae, and Trichechidae families, due to their predominantly aquatic habits. We also excluded species range polygons with presence values 3 (“possibly extant”) and 6 (“presence uncertain”), as well as with origin values 3 (“introduced”) and 4 (“vagrant”), avoiding highly uncertain records and keepin..., , # Data from: Future palaeontologists will detect current mammal latitudinal biodiversity gradient

[https://doi.org/10.5061/dryad.612jm64db](https://doi.org/10.5061/dryad.612jm64db)

## Description of the data and file structure

Code and data for running the analyses in the article \"Future palaeontologists will detect current mammal latitudinal biodiversity gradient\". This repository includes the species presence/absence databases, the fossil ocurrences database, and the R scripts used for processing and analysing.

### Files and variables

* \"Fossil_bias_LDG_script.R\" : R code for running the main text consecutive bias-simulating workflow (one replicate, Time-unlimited approach). It includes the code for processing the data, running analyses, and generating the figures.
* \"Fossil_bias_LDG_script_replicates.R\":  Code for running the consecutive bias-simulating workflow for the remaining replicates (Time-unlimited approach). It includes the code for processing the data, running analyses...,