DOI: 10.5061/dryad.9kd51c5g6
title: Data from: A method for mapping morphological convergence on three-dimensional digital models: the case of the mammalian saber-tooth

description: Morphological convergence can be assessed through a variety of statistical
 methods. None of the methods proposed to date enable the visualization of
 convergence. All are based on the assumption that the phenotypes either
 converge, or do not. However, between species, morphologically similar
 regions of a larger structure may behave differently. Previous approaches
 do not identify these regions within the larger structures or quantify the
 degree to which they may contribute to overall convergence. Here we
 introduce a new method to chart patterns of convergence on
 three-dimensional models, deployed with the R function conv.map. The
 convergence between pairs of models is mapped onto them to visualize and
 quantify the morphological convergence. We applied conv.map to a
 well-known case study, the saber-tooth morphotype which has evolved
 independently among distinct mammalian clades, from placentals to
 metatherians. Although previous authors have concluded that saber-tooths
 kill using a stabbing ‘bite’ to the neck, others have presented different
 interpretations for specific taxa, including the iconic Smilodon and
 Thylacosmilus. Our objective was to identify any shared morphological
 features among the saber-tooths that may underpin similar killing
 behaviours. From a sample of 49 placental and metatherian carnivores, we
 found stronger convergence among saber-tooths than for any other taxa. We
 found that the morphological convergence is most apparent in the rostral
 and posterior parts of the cranium. The extent of this convergence implies
 similarity in function among these phylogenetically distant species. In
 our view this function is most likely the killing of relatively large prey
 by a stabbing bite.
description: 1. Title of Dataset: Data from: A method for mapping
 morphological convergence on three-dimensional digital models: the case of
 the mammalian saber-tooth 2. Author
 Information<br>     A. First author Contact Information<br>   
      Name: Marina Melchionna<br>         Institution: DiSTAR -
 University of Naples Federico II<br>         Address: Via Cinthia,
 21 - 80126, Monte Sant’Angelo, Naples<br>         Email:
 marina.melchionna@unina.it     B. Corresponding author
 Contact Information<br>         Name: Pasquale Raia<br>       
  Institution: DiSTAR - University of Naples Federico II<br>       
  Address: Via Cinthia, 21 - 80126, Monte Sant’Angelo, Naples<br>   
      Email: pasquale.raia@unina.it DATA & FILE
 OVERVIEW - File List:  Appendix
 S1.docx: a general overview of all supplementary materials and methods
 included in the manuscript. tree.txt: phylogenetic tree
 in Newick format. Table S1.csv: list of used specimens
 with ID code, sex and museum location. F = female, M = male, U =
 unknown. Table S2.csv: anatomical definition of sampled
 landmarks on each specimen. Fig. S1.tif: landmark
 configuration (blue) and semilandmark patch (yellow) used in the
 analysis.  Fig. S2.tif: the process of retrodeformation
 on Barbourofelis fricki. A-B, the specimen before and after the
 retrodeformation process. C, the original specimen showing the modified
 areas during the retrodeformation in terms of expansion (blue) and
 contraction (red). Fig. S3.tif: the process of
 retrodeformation on Homotherium serum. A-B, the specimen before and after
 the retrodeformation process. C, the original specimen showing the
 modified areas during the retrodeformation in terms of expansion (blue)
 and contraction (red). Fig. S4.tif: illustration of the
 workflow followed to perform conv.map. A. We first performed a Principal
 Component Analysis on the sample. B. We used the search.conv function
 (‘RRphylo’ R package) to identify convergent species. C. We performed a
 Relative Warp Analyses on the shape data, setting the alpha parameter to
 1. The RW scores obtained by RWA were fed to conv.map to select the axes
 best-embodying convergence, by using the ede function (‘inflection’ R
 package). After the RW axes were selected, their scores were used to
 compute pairwise angle distances between species. D. conv.map plots
 highlighting the areas responsible for convergence (in blue).
 data.RDA: data used in the manuscript, any relevant information
 can be found in the script file. script.R: script to
 perform the analyses with the R Cran software.