10.5061/DRYAD.6JK8416
Lukic-Walther, Marcus
Freie Universität Berlin
Brocklehurst, Neil
Leibniz-Institut für Evolutions- und Biodiversitätsforschung
Kammerer, Christian F.
Humboldt University of Berlin
Fröbisch, Jörg
Data from: Diversity patterns of non-mammalian cynodonts (Synapsida,
Therapsida) and the impact of taxonomic practice and research history on
diversity estimates
Dryad
dataset
2018
Triassic
Permian
completeness
Bias
Cynodontia
2018-09-18T21:29:04Z
2018-09-18T21:29:04Z
en
https://doi.org/10.1017/pab.2018.38
41907823 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Non-mammalian cynodonts represent a speciose and ecologically diverse
group with a fossil record stretching from the late Permian until the
Cretaceous. Because of their role as major components of Triassic
terrestrial ecosystems and as the direct ancestors of mammals, cynodonts
are an important group for understanding Mesozoic tetrapod diversity. We
examine patterns of non-mammalian cynodont species richness and the
quality of their fossil record. A supertree of cynodonts is constructed
from recently published trees and time-calibrated using a Bayesian
approach. While this approach pushes the root of Cynodontia back to the
earliest Guadalupian, the origins of Cynognathia and Probainognathia are
close to their first appearance in the fossil record. Taxic, subsampled
and phylogenetic diversity estimates support a major cynodont radiation
following the end-Permian mass extinction, but conflicting signals are
observed at the end of the Triassic. The taxic diversity estimate shows
high diversity in the Rhaetian and a drop across the Triassic/Jurassic
boundary, while the phylogenetic diversity indicates an earlier extinction
between the Norian and Rhaetian. The difference is attributed to the
prevalence of taxa based solely on teeth in the Rhaetian, which are not
included in the phylogenetic diversity estimate. Examining the
completeness of cynodont specimens through geological time does not
support a decrease in preservation potential; although the median
completeness score decreases in the Late Triassic, the range of values
remains consistent. Instead, the poor completeness scores are attributed
to a shift in sampling and taxonomic practices: an increased prevalence in
microvertebrate sampling and the naming of fragmentary material.
Supplementary Data 1Completeness scores, first and last appearences,
number of specimens and skull lengths (mm) of the cynodont species
included in this studySupplementary Data 2Source trees used to create the
supertreeSupplementary Data 3R object ("hedmans") containing all
100 time calibrated phylogenies.Supplementary Data 4Characters used to
assign percentages to skeletal regions. Characters on the same row are
deemed to be identical or non-independentSupplementary Data 5Percentage
score assigned to each skeletal regionSupplementary Data 6Kendall's
Tau and p values of correlations between skull length and completeness,
using all 100 trees to calculate phylogenetic independent contrasts