This file details data and R script files for:

Couzens, A. M. C, King, B. & Prideaux, G. J. 2026. Contingent evolution of thick enamel by kangaroos to resist dietary abrasion. Science 392,488-492.DOI:10.1126/science.aeb2502

Please direct questions to Aidan Couzens: aidan.couzens[at]outlook[dot]com

Data folder

This folder contains data files needed to reproduce analyses and main paper plots.

data

Butler_etal_2017_bmass_max.csv: Body mass estimates for extinct Riversleigh kangaroos from Butler et al. (2017). Columns are fossil species, higher-level clade affiliation, and body mass in grams.

EXP_Bmass_taxa.csv: Exported compilation of body mass estimates for mammalian taxa. Columns as follows:

• "bmass_tax", taxon name;
• "mass_g", body mass in grams.

EXP_summary_enamel_data.csv: Exported summary data for macropodoid taxa. Column abbreviations:

• "Taxon", taxonomic assignment;
• "Clade", higher level taxonomic assignment;
• "mean_EVOL", mean enamel volume (mm3);
• "mean_RET3D", mean three dimensional relative enamel thickness;
• "mean_EI", mean enamel investment index, measured as enamel volume/body mass * 100;
• "mass_g", mean body mass in grams;
• "mean_HCA", mean relative linear enamel thickness of the hypoconid cusp apex.

EVOL_primate_bmass.csv: Compilation of primate lower molar enamel data and body mass estimates from various studies. Columns:

• "Genus", generic assignment;
• "Species", species assignment;
• "Order", ordinal assignment;
• "Family", family assignment;
• "Clade", species assignment;
• "ID", a useful higher level division;
• "Side", left or right side of jaw for enamel data;
• "Tooth_identity", lower molar position for enamel data;
• "Status", identified whether fossil or modern taxon;
• "Locality", fossil locality for enamel data;
• "Wt_g", body mass in grams;
• "Wt_source", literature source for weight estimate;
• "Wt_comment", remarks on how weight estimate computed if composite;
• "Voxel_size_um", voxel size of original scan data in microns;
• "EnamVOL_mm3", enamel volume in mm3;
• "EDJ_3D_Area_mm2", surface area of the enamel-dentine junction in mm2;
• "CorDVOL_filled_mm3", volume of the coronal dentine in mm3;
• "Evol_comment", literature source for enamel data.

fam_data.csv: Taxonomic and ecological data for marsupial herbivore families.

Helgen_etal_2006_bmass.csv: Body mass estimates for extinct sthenurine kangaroos from Helgen et al. (2006). Columns as for Butler data.

main_data_file.csv: Enamel thickness and tooth dimension data from fossil and modern macropodoid. Column abbreviations:

• "Specimen_number", specimen accession number;
• "Taxon", taxonomic assignment;
• "Est_age_Ma", estimated age in millions of years;
• "Side", defines if the specimen is from the left or right side of the lower jaw;
• "TI", molar tooth position from most anterior ("1") to most posterior ("4");
• "Subclade", lower-level taxonomic assignment;
• "Clade", higher-level taxonomic assignment;
• "Status", defines if the specimen is fossil or modern;
• "Assemblage", fossil assemblage;
• "Prtld_Wmax_mm", maximum width of protolophid in mm;
• "Prtld_Wcervix_mm", maximum width of protolophid at enamel cervix in mm;
• "Lmax_mm", maximum length of tooth crown in mm;
• "Lcervix_mm", maximum length of tooth crown at the enamel cervix in mm;
• "Hypld_Wmax_mm", maximum width of the hypolophid in mmm;
• "Hypld_Wcervix_mm", maximum width of hypolophid at the enamel cervix in mm;
• "AHB_mm", linear enamel thickness of the anterior face of the hypolophid (buccal half) in mm;
• "AHL_mm", linear enamel thickness of the anterior face of the hypolophid (lingual half) in mm;
• "INT_mm", linear enamel thickness of the interlophid basin in mm;
• "TRG_mm", linear enamel thickness of the trigonid basin floor in mm;
• "AP_mm", linear enamel thickness of the anterior face of the protolophid (lingual half) in mm;
• "PP_mm", linear enamel thickness of the posterior face of the protolophid (lingual half) in mm;
• "HYPCD_mm", linear enamel thickness of the hypoconid cusp apex in mm;
• "EVOL_mm3", crown enamel volume in mm3;
• "EDJSA_mm2", surface area of the enamel dentine junction in mm2;
• "DVOL_mm3", dentine volume within the enamel cap in mm3. Dentine volume cropped using a flat fill of enamel cervix;
• "Relief_angle", angle in degrees of the anterior inclination of the hypolophid relative to the buccal-side enamel cervix.
• "blade_depth_length_mm", distance between the mid point of the protolophid and hypoplophid.
• "blade_depth_theta", top angle between used to compute blade depth.
• "lingual_depth_mm", distance from lingual hypolophid cervix to the entoconid cusp tip.

mars_herb_data.csv:

• "Molar Type", classification of crown type;
• "Gazetted locality", locality of fossil;
• "Formation", formation from which the fossil was derived, if known;
• "Subepoch_Epoch", composite time interval for binning taxonomic richness data.

merged_tree_poly.tre: Composite phylogenetic tree;

species_diet.csv: Dietary classification of macropodoid species;
"Diet": "B" (=browser), "F" (= fungivore), "FR" (= frugivore), "G" (= grazer), "MF" (= mixed-feeder).

stage_list.csv: Start and end ages of geological stages used for time binning. Time units are in millions of years before present ("ma").

/data/maps

Data from historgrams of enamel thickness distribution exported from Avizo. Column explanations:

• Column one; enamel thickness (from thinnest to thickest down row) in mm;
• Column two; percent frquency of enamel thickness increment;
• Column three; cumulative enamel thickness percentile.

Files in this directory:

• AMF30626A_Simosthenurus_pales_Sthenurinae_NA_Bil_LMX.csv
• AMM1900_Dendrolagus_lumholtzi_Dendrolagini_B_Bil_LRM3.csv
• AMM1904_Dendrolagus_lumholtzi_Dendrolagini_B_Bil_LLM3.csv
• CM12696_Hypsiprymnodon_moschatus_Hypsiprymnodontidae_Fr_Bun_LRM3.csv
• CM12696_Hypsiprymnodon_moschatus_Hypsiprymnodontidae_Fr_Bun_LRM4.csv
• CM13430_Hypsiprymnodon_moschatus_Hypsiprymnodontidae_Fr_Bun_LRM3.csv
• CM13430_Hypsiprymnodon_moschatus_Hypsiprymnodontidae_Fr_Bun_LRM4.csv
• FU2001.9.23.47_Osphranter_rufus_Macropodini_G_Bil_LLMX.csv
• FUR078_Pseudocheirus_peregrinnus_Pseuocheiridae_B_Bunsel_LMX.csv
• FUR224_Trichosurus_vulpecula_Phalangeridae_OM_Bunl_LRMX.csv
• SAMM55_Setonix_brachyurus_Macropodini_B_Bil_LRM3.csv
• SAMM5149_Onychogalea_unguifera_Macropodini_MF_Bil_LRM3.csv
• QMF57500_Wanburoo_hilarus_Sthenurinae_NA_Bil_MX.csv
• QMJ20860_Osphranter_robustus_Macropodini_G_Bil_LRM3.csv
• SAMM7493_Potorous_tridactylus_Potoroinae_Fu_Bunl_LRM4.csv
• SAMM8658_Potorous_tridactylus_Potoroinae_Fu_Bunl_LLM3.csv
• SAMM8658_Potorous_tridactylus_Potoroinae_Fu_Bunl_LLM4.csv
• SAMM15918_Aepyrymnus_rufescens_Potoroinae_Fu_Bunl_LRM4.csv
• SAMM15919_Aepyrymnus_rufescens_Potoroinae_Fu_Bunl_LLM3.csv
• SAMP27068_Procoptodon_goliah_Sthenurinae_NA_Bil_LMX.csv
• SAMP28663_Simosthenurus_occidentalis_Sthenurinae_NA_Bil_LLMX.csv
• SAMP47109_Procoptodon_goliah_Sthenurinae_NA_Bil_LMX.csv
• UCMP65961_Hadronomas_puckridgi_Sthenurinae_NA_Bil_LLM2.csv
• WAMM5669_Lagostrophus_fasciatus_Lagostrophinae_MF_Bil_LLMX.csv

/data/pdbd_genera

Time binned generic richness occurrence data for placental herbivore families exported from the Paleobiology Database. See the "pbdb_occurrences" function in R for additional information about the exported occurrence data format. Refer to https://paleobiodb.org/data1.2/occs/list for detailed explanations of variables.

Column abbreviations:

• "occurrence_no"; unique identifier for this occurrence.
• "record_type"; the type of this object: occ for an occurrence.
• "collection_no"; The identifier of the collection with which this occurrence is associated.
• "identified_name"; The taxonomic name by which this occurrence was identified.
• "identified_rank"; The taxonomic rank of the identified name, if this can be determined.
• "identified_no"; The unique identifier of the identified taxonomic name.
• "accepted_name"; Accepted taxonomic name.
• "accepted_rank"; The taxonomic rank of the accepted name.
• "accepted_no"; The unique identifier of the accepted taxonomic name.
• "early_interval"; The geologic time range associated with occurrence.
• "max_ma"; The early bound of the geologic time range associated with this occurrence (in Ma).
• "min_ma"; The late bound of the geologic time range associated with this occurrence (in Ma).
• "reference_no"; The identifier of the reference from which this data was entered.
• "phylum"; The name of the phylum in which this occurrence is classified.
• "phylum_no"; The identifier of the phylum in which this occurrence is classified.
• "class"; The name of the class in which this occurrence is classified.
• "class_no"; The identifier of the class in which this occurrence is classified.
• "order"; The name of the order in which this occurrence is classified.
• "order_no"; The identifier of the order in which this occurrence is classified.
• "family"; The name of the family in which this occurrence is classified.
• "family_no"; The identifier of the family in which this occurrence is classified.
• "genus"; The name of the genus in which this occurrence is classified.
• "genus_no"; The identifier of the genus in which this occurrence is classified.
• "time_bins"; Time intervals into which this occurrence is placed according to timerule selected.
• "difference"; Explanation for any difference from accepted name, if relevant.

Files in this directory:

• aplodontidae.csv
• arctostylopidae.csv
• astrapotheriidae.csv
• brontotheriidae.csv
• carodniidae.csv
• cercopithecoidea.csv
• chlamyphoridae.csv
• coryphodontidae.csv
• deinotheriidae.csv
• embrithopoda.csv
• equidae.csv
• hegetotheriidae.csv
• henricosborniidae.csv
• hippopotamidae.csv
• hyopsodontidae.csv
• hyracoidea.csv
• interatheriidae.csv
• leontiniidae.csv
• leporidae.csv
• lophiodontidae.csv
• macraucheniidae.csv
• mammutidae.csv
• megatheriidae.csv
• mesotheriidae.csv
• mioclaenidae.csv
• notohippidae.csv
• numidotheriidae.csv
• ochotonidae.csv
• pampatheriidae.csv
• pantodonta.csv
• paraceratheriidae.csv
• periptychidae.csv
• phenacodontidae.csv
• procaviidae.csv
• proterotheriidae.csv
• pyrotheriidae.csv
• rhinocerotidae.csv
• ruminantia.csv
• taeniodonta.csv
• tapiridae.csv
• tillodontia.csv
• toxodontidae.csv
• trichechidae.csv
• uintatheriidae.csv
• xenungulata.csv

R Scripts folder

This folder contains R script files needed to reproduce analyses and plots reported in Couzens et al. (this work).

• bmass.R: Compiles body mass data for primates and macropodoids for later analysis. Input files are MOMv3.3.txt data file from Smith et al. (2003) (https://figshare.com/collections/BODY_MASS_OF_LATE_QUATERNARY_MAMMALS/3297995), "EVOL_primate_bmass.csv", "Helgen_etal_2007_bmass.csv", "Butler_etal_2017_bmass_max.csv". Exports "EXP_Bmass_taxa.csv".

• table_exp.csv: Merges enamel data and body mass for macropodoids and primates and exports a summary data set for later analysis. Input files are "main_data_file.csv" and "EXP_Bmass_taxa.csv". Exports "EXP_summary_enamel_data.csv".

• tree_construct_poly.R: Generates a composite phylogenetic tree of fossil and extant macropodoids. Input files are the tip-dated phylogenetic tree of Cascini et al. (2019) and the MCMCtree time-calibrated phylogeny based on RAXML analysis of 193 taxa with branch lengths in millions of years from Mitchell et al. (2014). Exports "merged_tree_poly.tre".

• fig2A_Genera_Richness_PBDB_5myr_bins.R: Analyses and plots placental herbivore richness through time. Input files are herbivore richness *.csv files in /data/pdbd_genera and "stage_list.csv". Reproduces figure 2A.

• fig2B_Genus_Richness_ALL_MARS_HERB_subepoch.R: Analyses and plots marsupial herbivore richness through time. Input files are "mars_herb_data.csv". Reproduces figure 2B.

• fig3A-D_ENAM_by_clade_BoxWhskr_Species.R: Produces box and whisker plot of clade-level variation in enamel thickness. Input file is "main_data_file.csv". Reproduces figure 3A-D.

• fig3E-H_ENAM_by_diet_BoxWhskr.R: Produces box and whisker plot of dietary variation in enamel thickness. Input files are "species_diet.csv" and "main_data_file.csv". Reproduces figure 3E-H.

• fig3I_PCA.R: Produces a principal component analysis of linear enamel thickness data. Input file is "EXP_summary_enamel_data.csv". Reproduces figure 3I.

• fig3J_macro_primate_3d_bmass.R: Produces a phylogenetic generalised least squares regression of enamel volume vs body mass in kangaroos and primates. Input files are "EXP_summary_enamel_data.csv","merged_tree_poly.tre", and the "consensusTree_10kTrees_Primates_Version3.nex" from Arnold et al. 2010. Please download this latter file separately. Reproduces figure 3J.

• fig4A_ASR_EVOL_bmass.R: Performs and plots an ancestral state reconstruction of enamel investment (EVOL in mm3/ body mass in grams) on a macropodoid phylogeny. Input files "merged_tree_poly.tre" and "EXP_summary_enamel_data.csv". Reproduces figure 4A.

• fig4B_RET3D_time_points_lines.R: Plots measurements of macropodoid RET3D through time. Also computes time-binned averages and plots clade-specific trend lines of macropodoid RET3D through time. Input file is "main_data_file.csv". Reproduces figure 4B.

• fig4C_EVOL_v_time_points_lines.R: Plots measurements of macropodoid molar enamel volume (mm3) through time. Input file is "main_data_file.csv". Computes time-binned averages and plots clade-specific trend lines for macropodoid enamel volume (mm3) through time. Reproduces figure 4C.

• fig4D_Linear_enamel_thickness_v_time_points_lines.R: Plots measurements of linear enamel thickness (mm) at the hypoconid apex vs. time. Also plots trend lines for different metrics of linear enamel thickness (mm) through time. Input file is "main_data_file.csv". Reproduces figure 4D.

• fig4E_Blade_depth_v_time_points_lines.R: Computes and plots measurements of molar blade depth through time. Also computes time-binned averages and plots trend lines for molar blade depth through time. Input file is "main_data_file.csv". Reproduces figure 4E.

• fig4F_Relief_angle_v_time_points_lines.R: Computes and plots measurements of molar blade relief angle through time. Also computes time-binned averages and plots trend lines for molar blade relief through time. Input file is "main_data_file.csv". Reproduces figure 4F.

• figS2_PCA_correlation.R: Computes and plots correlation between principal component scores and linear enamel metrics. Input files are "EXP_summary_enamel_data.csv", "main_data_file.csv", and "species_diet.csv". Reproduces figures S2.

• figS4E-F_ET_dist_Sthenurine.R: Computes and plots absolute and relative enamel thickness distribution profiles. Imports enamel distribution files in *.csv files in "/data/maps". Reproduces figure S4E and F.

• figS9_Tooth_dim_bmass.R: Computes and plots phylogenetic and ordinary least squares regressions of tooth dimensions against body mass. Input files are "merged_tree_poly.tre" and "main_data_file.csv".

References

Arnold, C., Matthews, L.J., Nunn, C.L. 2010. The 10kTrees website: A new online resource for primate phylogeny. Evol. Anthrop. 19:114-118.

Butler, K. et al. 2017. Species abundance, richness and body size evolution of kangaroos (Marsupialia: Macropodiformes) throughout the Oligo-Miocene of Australia. Palaeogeo, Palaeoclim. Palaeoeco. 487:25–36.

Cascini, M., Mitchell, K.J., Cooper, A. and Phillips, M.J., 2019. Reconstructing the evolution of giant extinct kangaroos: comparing the utility of DNA, morphology, and total evidence. Syst. Biol. 68:520-537.

Couzens, A. M. C., King, B., Prideaux, G.J. Contingent evolution of thick enamel by kangaroos to resist dietary abrasion. Science [this work].

Couzens, A. M. C. & Prideaux, G.J. 2018. Rapid Pliocene adaptive radiation of modern kangaroos. Science 362:72-75.

Froehle, A.W. & Churchill, S.E., 2009. Energetic competition between Neandertals and anatomically modern humans. PaleoAnthropology, 2009, pp.96-116.

Gordon, A.D. 2006. Scaling of size and dimorphism in primates II: Macroevolution. Int. J. Primatol. 27:63–105.

Grabowski, M., Hatala, K.G., Jungers, W.L. and Richmond, B.G., 2015. Body mass estimates of hominin fossils and the evolution of human body size. J. Hum. Evol. 85:75-93.

Helgen, K. M. et al. 2006. Ecological and evolutionary significance of sizes of giant extinct kangaroos. Aus. J. Zool. 54:293-303.

Isler, K. et al. 2008. Endocranial volumes of primate species: scaling analyses using a comprehensive and reliable data set. J. Hum. Evol. 55:967-978.

Mitchell, K. J. et al. 2014. Molecular phylogeny, biogeography, and habitat preference evolution of marsupials. Mol. Phylog. Evol. 31:2322-2330.

Olejniczak, A. J., et al. 2008a. Dental tissue proportions and enamel thickness in Neandertal and modern human molars. J. Hum. Evol. 55: 12-23.

Olejniczak, A. J., et al. 2008b. Three-dimensional molar enamel distribution and thickness in Australopithecus and Paranthropus. Biol. Lett. 4:406-410.

Olejniczak, A. J., et al. 2008c.Three-dimensional primate molar enamel thickness. J. Hum. Evol. 54:187-195.

Smith, F. A. et al. 2003. Body mass of late Quaternary mammals. Ecol. 84:3403–3403.

Smith, R. J. & Jungers, W. L. 1997. Body mass in comparative primatology. J. Hum. Evol. 32:523-559.