DOI: 10.5061/dryad.vr157
title: Data from: Body size and extinction risk in terrestrial mammals above the species level

description: Mammalian body mass strongly correlates with life history and population
 properties at the scale of mouse to elephant. Large body size is thus
 often associated with elevated extinction risk. I examined the North
 American fossil record (28–1 million years ago) of 276 terrestrial genera
 to uncover the relationship between body size and extinction probability
 above the species level. Phylogenetic comparative analysis revealed no
 correlation between sampling-adjusted durations and body masses ranging 7
 orders of magnitude, an observation that was corroborated by survival
 analysis. Most of the ecological and temporal groups within the data set
 showed the same lack of relationship. Size-biased generic extinctions do
 not constitute a general feature of the Holarctic mammalian faunas in the
 Neogene. Rather, accelerated loss of large mammals occurred during
 intervals that experienced combinations of regional aridification and
 increased biomic heterogeneity within continents. The latter phenomenon is
 consistent with the macroecological prediction that large geographic
 ranges are critical to the survival of large mammals in evolutionary time.
 The frequent lack of size selectivity in generic extinctions can be
 reconciled with size-biased species loss if extinctions of large and small
 mammals at the species level are often driven by ecological perturbations
 of different spatial and temporal scales, while those at the genus level
 are more synchronized in time as a result of fundamental, multiscale
 environmental shifts.
description: Fossil Occurrence
 DataFossil occurrence data
 compiled from the MIOMAP and FAUNMAP databases
 (http://www.ucmp.berkeley.edu/neomap/). Each locality is identified by the
 combination of database name (“MM” for MIOMAP, “FM” for FAUNMAP), Machine
 Number, and Analysis Unit. Included in the data table are: Max_age,
 maximum age of locality in million years; Min_age, minimum age of locality
 in million years; Genus_accepted, standardized genus designation;
 Species_accepted, standardized species designation; Genus_NEOMAP, genus
 designation in MIOMAP/FAUNMAP; Species_NEOMAP, species designation in
 MIOMAP/FAUNMAP; ID_conf_NEOMAP, level of confidence in the original
 species identification.Dryad_Tomiya Fossil Occurrence
 Data.csvCladogramComposite cladogram for 276 North American fossil genera. See article and Online Appendix B for complete sources of information.Dryad_Tomiya Cladogram.nexBody Mass DataSkeletal measurements and estimated body masses of 901 taxa. Refer to Online Appendix B for additional information. Included in the data table are: LnMass, natural-log transformed body mass (originally in grams); m1L, anteroposterior length of the lower first molar; m1W, transverse width of the lower first molar; otherL, anteroposterior length of a skeletal element other than m1 (reported under Remarks); otherW, transverse width of a skeletal element other than m1 (reported under Remarks). See Body Mass References for a list of literature sources of measurements. Measurement data in the Paleobiology Database were obtained from: http://paleodb.org/cgi-bin/bridge.pl.Dryad_Tomiya Body Mass Data.csvBody Mass ReferencesLiterature sources of skeletal measurements reported in Body Mass Data.Dryad_Tomiya Body Mass References.pdfGeneric DataGeneric data for phylogenetic comparative analyses. Included in the data table are: Group1/2, taxonomic affiliation above the genus level; Occurrences, number of genus-level occurrences in North America; T_FAD, observed first appearance date; T_LAD, observed last appearance date; T_FAD50, sampling-adjusted first appearance date; T_LAD, sampling-adjusted last appearance date; LnMass, natural-log transformed estimated body mass (originally in grams); LnIBIL, natural-log transformed expected inter-birth interval length (originally in days).Dryad_Tomiya Generic Data.csv