Morphological integration and functional modularity in the crocodilian skull

Author(s)
Piras, Paolo
Buscalioni, Angela D
Teresi, Luciano
Raia, Pasquale
Sansalone, Gabriele
Kotsakis, Tassos
Cubo, Jorge
Publication Date
2014-08
Abstract
We explored the morphological organization of the skull within Crocodylidae, analyzing functional and phylogenetic interactions between its 2 constituent functional modules: the rostrum and the postrostrum. We used geometric morphometrics to identify localized shape changes, focusing on the differences between the major clades of the crown-group Crocodylia: Alligatoridae and Crocodylidae. We used published bite performance data to correlate rostral function with postrostral morphology. The skull modules appear more integrated within Alligatoridae than within Crocodyliade. Phylogenetic effects on shape variation are more evident in Alligatoridae than in Crocodylidae, where functional parameters concerning the rostral morphology are proportionally more important than phylogeny. Long-snouted species are characterized by low structural performance, which is significantly associated with a reduction of the pterygoid-quadrate cranial nipper, suggesting that the nipper is important for the ingestion of large food items in generalist species. This functional association is coupled with a significant evolutionary allometry at the clade level, while Alligatoridae and Crocodylidae show different degrees of evolutionary allometry for their entire shape and rostrum. The postrostrum is more conservative than the rostrum in terms of morphospace occupation, evolutionary allometry and phylogenetic signal.
Citation
Integrative Zoology, 9(4), p. 498-516
ISSN
1749-4877
1749-4869
Pubmed ID
25236418
Link
Publisher
Wiley-Blackwell Publishing Ltd
Title
Morphological integration and functional modularity in the crocodilian skull
Type of document
Journal Article
Entity Type
Publication

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