10.5061/DRYAD.0K6DJH9XC
Melstrom, Keegan
0000-0002-6313-6146
Natural History Museum of Los Angeles County
Angielczyk, Kenneth
Field Museum of Natural History
Ritterbush, Kathleen
University of Utah
Irmis, Randall
University of Utah
The limits of convergence: the roles of phylogeny and dietary ecology in
shaping non-avian amniote skulls
Dryad
dataset
2020
Amniotes
Cranial morphology
Amniotes
Cranial morphology
Macroevolution
2020-08-04T00:00:00Z
2020-08-04T00:00:00Z
en
698065826 bytes
7
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Cranial morphology is remarkably varied in living amniotes, ranging from
short-faced mammals to the elongate snouts of crocodylians. This diversity
of shapes is thought to correspond with feeding ecology, a relationship
repeatedly demonstrated at smaller phylogenetic scales, but one that
remains untested across amniote phylogeny. Using a combination of 2D
geometric and linear morphometrics, we investigate the links between
phylogenetic relationships, diet, and skull shape in an expansive dataset
of extant amniotes with teeth: mammals, lepidosaurs, and crocodylians. We
find that both phylogeny and diet have statistically significant effects
on skull shape, although these effects differ depending on the dataset
analyzed. The three major clades largely partition morphospace, each
plotting in separate regions with limited overlap. Mammals and squamates
extensively diversify within their respective regions. Among all three
groups, dietary generalists often occupy clade-specific central regions of
morphospace. Some parallel changes in skull shape occur in clades with
distinct evolutionary histories but similar diets. However, members of a
given clade often present distinct skull shape solutions for a given diet,
and the vast majority of species retain the unique aspects of their
ancestral skull plan, underscoring the limits of morphological convergence
due to ecology in amniotes. These data demonstrate that certain skull
shapes may provide functional advantages suited to particular diets, but
accounting for both phylogenetic history and ecology can provide a more
nuanced approach for inferring the ecology and functional morphology of
cryptic or extinct amniotes.