Predicting body length and assessing the shape of tail-propelled Mesozoic marine reptiles
Data files
Aug 31, 2025 version files 79.68 KB
-
README.md
2.52 KB
-
SuppInfo.zip
77.16 KB
Abstract
Body length is a crucial ecological predictor in vertebrates, yet total body length proxies have seldom been assessed for ancient marine top predators. Here, we test the strength of phylogenetic imputation and 23 linear measurements, sampling both broad skeletal regions and frequently fossilised elements (such as vertebral centra), in predicting the body length of the main clades of tail-propelled Mesozoic marine reptiles (Ichthyosauria, Mosasauridae, and pelagic thalattosuchians). We embed this marine reptile sample within a comparative framework with raptorial cetaceans, and analyse the evolution of body proportions in these clades. We find that trunk length and centrum dimensions are strong predictors of body length, opening up the possibility to build vast datasets of body length estimations for Mesozoic marine reptiles from minimal preserved remains. We provide body length calculation equations for all traits and all clades. Proxies fared much better and often had distinct slopes when applied clade-wide rather than when applied to the global dataset. We also show that body length in Mesozoic marine reptiles is more labile than their skeletal architectures, rendering phylogenetic imputation methods less effective than skeletal proxies for assessing body lengths.
Dataset DOI: 10.5061/dryad.4xgxd25nh
Description of the data and file structure
The .zip file (SuppInfo.zip) is a compressed folder which can be uncompressed with software like winzip, winrar, the unarchiver. It contains:
- The raw data (linear measurements in mm of total bodies and body parts, per species, in an Excel file:
SuppData1.xslx). This is an Excel file that can be opened with Microsoft Excel, Open Office, Google Sheets, or R. - The phylogenetic data trees (one dataset for each focal clade, in the .tre format:
SuppData2_Cetacea.tre[Cetacea],SuppData3_Ichthyosauria.tre[Ichthyosauria],SuppData4_Mosasauridae.tre[Mosasauridae],SuppData5_Thalattosuchia.tre[Thalattosuchia]). These are files containing information on the phylogenetic relationships of the species of interest. Such a file can be opened with Mesquite, R. These data are dimensionless. - The results from all analyses (coefficient of correlation: R2, slope of the regression line, intercept of the regression line, standard error of the correlation, for both the ordinary least square [OLS] and phylogenetic generalised least square [PGLS] analyses) and each clade, in a .csv format (
SuppData6.csv[all species combined],SuppData7.csv[all reptiles combined],SuppData8.csv[Cetacea],SuppData9.csv[Ichthyosauria],SuppData10.csv[multivariate regressions; Ichthyosauria],SuppData11.csv[Mosasauridae],SuppData12.csv[multivariate regressions; Mosasauriae],SuppData13.csv[Thalattosuchia],SuppData14.csv[multivariate regressions; Thalattosuchia]). CSV is an efficient way to store information from a matrix into a text file. It can be opened using Microsoft Excel, Open Office, Google Sheets, R. These data are dimensionless. - The R script,
SuppData15_Rscript.R, (in .r format) used to call all the necessary packages, import the data, and generate all results and the base of all figures. The script contains explanations throughout and can be opened in R, Rstudio. The following packages are used: AICcmodavg, ape, dplyr, FSA, ggalt, ggplot2, ggpubr, ggtern, paleotree, phylolm, phytools, picante, psych, readxl, Rphylopars #optional, just to test if results are similar to those of picante, strap, tidyr, viridis.
Access information
Other publicly accessible locations of the data: