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Skull Reconstructions of Theropods and Basal Saurischians

From: Ben Creisler

New in PLoS ONE:

Christian Foth  and Oliver W. M. Rauhut (2013)
The Good, the Bad, and the Ugly: The Influence of Skull
Reconstructions and Intraspecific Variability in Studies of Cranial
Morphometrics in Theropods and Basal Saurischians.
PLoS ONE 8(8): e72007.

Several studies investigating macroevolutionary skull shape variation
in fossil reptiles were published recently, often using skull
reconstructions taken from the scientific literature. However, this
approach could be potentially problematic, because skull
reconstructions might differ notably due to incompleteness and/or
deformation of the material. Furthermore, the influence of
intraspecific variation has usually not been explored in these
studies. Both points could influence the results of morphometric
analyses by affecting the relative position of species to each other
within the morphospace. The aim of the current study is to investigate
the variation in morphometric data between skull reconstructions based
on the same specimen, and to compare the results to shape variation
occurring in skull reconstructions based on different specimens of the
same species (intraspecific variation) and skulls of closely related
species (intraspecific variation). Based on the current results, shape
variation of different skull reconstructions based on the same
specimen seems to have generally little influence on the results of a
geometric morphometric analysis, although it cannot be excluded that
some erroneous reconstructions of poorly preserved specimens might
cause problems occasionally. In contrast, for different specimens of
the same species the variation is generally higher than between
different reconstructions based on the same specimen. For closely
related species, at least with similar ecological preferences in
respect to the dietary spectrum, the degree of interspecific variation
can overlap with that of intraspecific variation, most probably due to
similar biomechanical constraints.