10.5061/DRYAD.5MKKWH75N
Tschopp, Emanuel
0000-0002-5245-6910
University of Hamburg
Napoli, James
American Museum of Natural History
Wencker, Lukardis
University of Turin
Delfino, Massimo
University of Turin
Upchurch, Paul
University College London
How to render species comparable taxonomic units through deep time: A case
study on intraspecific osteological variability in extant and extinct
lacertid lizards
Dryad
dataset
2021
morphological disparity
Osteology
intraspecific variation
Lacertidae
taxonomic bias
species
FOS: Biological sciences
Genetics
Ecology, Evolution, Behavior and Systematics
European Commission
https://ror.org/00k4n6c32
Marie Skłodowska–Curie grant agreement No. 609402-2020 researchers:
Train to Move (T2M)
European Commission
https://ror.org/00k4n6c32
FR-TAF-5839
European Commission
https://ror.org/00k4n6c32
AT-TAF-5725
Erasmus+
https://ror.org/01v2m4n16
2 Traineeships for LCM Wencker
Richard Gilder Graduate School**
PhD fellowship for JG Napoli
American Museum of Natural History
https://ror.org/03thb3e06
Newt and Callista Gingrich endowment
University of Turin
https://ror.org/048tbm396
PhD fellowship for LCM Wencker
University of Turin
https://ror.org/048tbm396
Fondi di Ricerca Locale UNITO 2017-2019
European Commission
https://ror.org/00k4n6c32
2021-10-27T00:00:00Z
2021-10-27T00:00:00Z
en
http://morphobank.org/permalink/?P4084
https://doi.org/10.1093/sysbio/syab078
https://doi.org/10.5281/zenodo.5603266
https://doi.org/10.5281/zenodo.5603268
3433637 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Generally, the species is considered to be the only naturally occurring
taxon. However, species recognized and defined using different species
delimitation criteria cannot readily be compared, impacting studies of
biodiversity through Deep Time. This comparability issue is particularly
marked when comparing extant with extinct species because the only
available data for species delimitation in fossils are derived from their
preserved morphology, which is generally restricted to osteology in
vertebrates. Here, we quantify intraspecific, intrageneric, and
intergeneric osteological variability in extant species of lacertid
lizards using pairwise dissimilarity scores based on a data set of 253
discrete osteological characters for 99 specimens referred to 24 species.
Variability is always significantly lower intraspecifically than between
individuals belonging to distinct species of a single genus, which is in
turn significantly lower than intergeneric variability. Average values of
intraspecific variability and associated standard deviations are
consistent (with few exceptions), with an overall average within a species
of 0.208 changes per character scored. Application of the same methods to
six extinct lacertid species (represented by 40 fossil specimens) revealed
that intraspecific osteological variability is inconsistent, which can at
least in part be attributed to different researchers having unequal
expectations of the skeletal dissimilarity within species units. Such a
divergent interpretation of intraspecific and interspecific variability
among extant and extinct species reinforces the incomparability of the
species unit. Lacertidae is an example where extant species recognized and
defined based on a number of delimitation criteria show comparable and
consistent intraspecific osteological variability. Here, as well as in
equivalent cases, application of those skeletal dissimilarity values to
paleontological species delimitation potentially provides a way to
ameliorate inconsistencies created by the use of morphology to define
species.
Personal visits to scientific collections by Emanuel Tschopp and Lukardis
Wencker. Some specimens were scored based on figures in published
literature. Python and R scripts were developed by Lukardis Wencker and
James Napoli, respectively.
The complete character matrix is also available on MorphoBank
(http://morphobank.org/permalink/?P4084), where sources for characters and
character scores are marked within the matrix as comments.