Description of the data and file structure Supp_info.docx: this is a text file that can be opened with Microsoft Word, Open Office, Google Docs. It contains text describing additional details of the method and supplementary figures (S1–S11). SI1_Raw_data_BM_EU.xlsx: this is an Excel file that can be opened with Microsoft Excel, Open Office, Google Sheets. It contains the data sources, locality, MP(s), dental measurements, and estimated body masses for each species of the European dataset. Each clade is separated in a tab. SI2_Bodymass_data_EU.xlsx: this is an Excel file that can be opened with Microsoft Excel, Open Office, Google Sheets, and is machine-readable in R. This is dataset used for all analyses, taking the log10(body mass) from SI1, for all sampled species (in the tab "BM"). The tab "Numerical_ages" contains the start and end numerical ages for all MP analysed (6 to 30). SI3_Juhn&al2024data.xlsx: this is an Excel file that can be opened with Microsoft Excel, Open Office, Google Sheets, and is machine-readable in R. This was downloaded from the supplementary information provided by Juhn et al 2024; we solely used the data under the tab "Fossil Data". It contains the max, min ages and the body mass (kg) for carnivorous species in North America. The other tab is called "NALMA" and provides the start and end numerical ages for all the NALMA subdivisions analysed. SI4_Westerhold&al.xlsx: this is an Excel file that can be opened with Microsoft Excel, Open Office, Google Sheets, and is machine-readable in R. This was downloaded from the supplementary information provided by Westerhold et al 2020; it contains a time series of smoothened / averaged d18O values and was only used to produce panel (a) of Figure 1. SI5_Faurby&al_nexus.nex: this is a nexus file containing a phylogenetic data matrix and phylogenetic trees, downloaded from the supplementary information provided by Faurby et al. 2024. It can be opened in Mesquite, any text editor and is also machine-readable in R. SI6_Rscript.R: this is a script used to call all the necessary packages, import the data, and generate all results and the base of all figures. The script contains chapters and explanations throughout and can be opened in R, Rstudio. It used the following functions: http://www.graemetlloyd.com/pubdata/functions_2.r (Age series detrending function by Dr. Graeme T. Lloyd), the surface pBIC functions.R and Trend shift functions.R which can be downloaded from the supplementary information provided by Benson et al. 2017, and the following packages: readxl, ape, phytools, vegan, dispRity, dplyr, castor, strap, paleotree, remotes, diptest, pbapply, ggplot2, ggpubr, gridExtra, geoscale, wesanderson. TableS1.xslx: this is an Excel file that can be opened with Microsoft Excel, Open Office, Google Sheets. It contains all the numerical results and statistical tests we produced. All these supplementary tables can be found as individualised tabs in the file. Tab A: body masses over time, all taxa, Europe. Tab B: body masses over time, early carnivoramorphans, Europe. Tab C: body masses over time, Carnivora, Europe. Tab D: body masses over time, all carnivoramorphans, Europe. Tab E: body masses over time, Hyaenodonta, Europe. Tab F: body masses over time, Oxyaenodonta, Europe. Tab G: body masses over time, Mesonychidae, Europe. Tab H: body masses over time, all taxa, USA. Tab I: body masses over time, early carnivoramorphans, USA. Tab J: body masses over time, Carnivora, USA. Tab K: body masses over time, all carnivoramorphans, USA. Tab L: body masses over time, Hyaenodonta, USA. Tab M: body masses over time, Oxyaenodonta, USA. Tab N: generalised differencing correlation tests. Tab O: results of phylogenetic models, European data. Tab P: tests of multimodality, European data. Tab Q: serialised KS tests, European data. Tab R: serialised KS tests, North American data. Access information Other publicly accessible locations of the data: Université de Liège institutional repository "Orbi"