Ontogenetic bite-force modeling of Alligator mississippiensis: implications for dietary transitions in a large-bodied vertebrate and the evolution of crocodylian feeding

Paul Gignac, G. M. Erickson

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Crocodylians undergo substantial increases in size during ontogeny. The American alligator, Alligator mississippiensis, in particular traverses nearly four orders of body mass between hatching and senescence. Accompanying such changes are modifications in rostrodental morphology and feeding capabilities that facilitate major shifts in diet. How such anatomical changes relate to ecological niche occupation across sizes is not well understood. In this study, we focused on the effects of ontogenetic changes on the force-generating mechanisms for jaw closure to assess the impacts of scaling on feeding biomechanics. We developed dissection-based, musculoskeletal models of maximum bite-force generation throughout ontogeny and compared and tested their veracity with data from an A. mississippiensis developmental series, for which bite forces were directly measured. Through examinations of the scaling patterns within the parameters of our models, we discuss how muscle pennation and positive allometry in the American alligator jaw adductor system facilitate capture strategies and oral processing of prey, and contribute to developmental niche shifts in this large-bodied taxon. On the basis of conservation of the crocodylian jaw adductor system, we argue that our findings are broadly applicable to crown Crocodylia and reflect an important, but often overlooked, aspect of the crocodylian feeding ecomorphology: littoral, sit-and-wait predation is enhanced by posteroventrally displaced, exceptionally large, and forceful ventral pterygoideus muscles, in particular. Future studies on the ontogeny and evolution of feeding in crocodylians should not neglect the functional and ecological implications of these muscles' contributions to diet.

Original languageEnglish
Pages (from-to)229-238
Number of pages10
JournalJournal of Zoology
Volume299
Issue number4
DOIs
StatePublished - 1 Aug 2016

Fingerprint

Alligator mississippiensis
Alligator (Alligatoridae)
jaws
ontogeny
vertebrate
vertebrates
muscles
muscle
niches
Crocodylia
modeling
ecomorphology
allometry
diet
biomechanics
mouth
dissection
senescence
hatching
predation

Keywords

  • Crocodylia
  • biomechanics
  • bite force
  • ecomorphology
  • feeding ecology
  • ontogeny
  • pennation
  • scaling

Cite this

@article{33b49de3169f46709e03c06ad59657ad,
title = "Ontogenetic bite-force modeling of Alligator mississippiensis: implications for dietary transitions in a large-bodied vertebrate and the evolution of crocodylian feeding",
abstract = "Crocodylians undergo substantial increases in size during ontogeny. The American alligator, Alligator mississippiensis, in particular traverses nearly four orders of body mass between hatching and senescence. Accompanying such changes are modifications in rostrodental morphology and feeding capabilities that facilitate major shifts in diet. How such anatomical changes relate to ecological niche occupation across sizes is not well understood. In this study, we focused on the effects of ontogenetic changes on the force-generating mechanisms for jaw closure to assess the impacts of scaling on feeding biomechanics. We developed dissection-based, musculoskeletal models of maximum bite-force generation throughout ontogeny and compared and tested their veracity with data from an A. mississippiensis developmental series, for which bite forces were directly measured. Through examinations of the scaling patterns within the parameters of our models, we discuss how muscle pennation and positive allometry in the American alligator jaw adductor system facilitate capture strategies and oral processing of prey, and contribute to developmental niche shifts in this large-bodied taxon. On the basis of conservation of the crocodylian jaw adductor system, we argue that our findings are broadly applicable to crown Crocodylia and reflect an important, but often overlooked, aspect of the crocodylian feeding ecomorphology: littoral, sit-and-wait predation is enhanced by posteroventrally displaced, exceptionally large, and forceful ventral pterygoideus muscles, in particular. Future studies on the ontogeny and evolution of feeding in crocodylians should not neglect the functional and ecological implications of these muscles' contributions to diet.",
keywords = "Crocodylia, biomechanics, bite force, ecomorphology, feeding ecology, ontogeny, pennation, scaling",
author = "Paul Gignac and Erickson, {G. M.}",
year = "2016",
month = "8",
day = "1",
doi = "10.1111/jzo.12349",
language = "English",
volume = "299",
pages = "229--238",
journal = "Journal of Zoology",
issn = "0952-8369",
publisher = "Wiley-Blackwell",
number = "4",

}

TY - JOUR

T1 - Ontogenetic bite-force modeling of Alligator mississippiensis

T2 - implications for dietary transitions in a large-bodied vertebrate and the evolution of crocodylian feeding

AU - Gignac, Paul

AU - Erickson, G. M.

PY - 2016/8/1

Y1 - 2016/8/1

N2 - Crocodylians undergo substantial increases in size during ontogeny. The American alligator, Alligator mississippiensis, in particular traverses nearly four orders of body mass between hatching and senescence. Accompanying such changes are modifications in rostrodental morphology and feeding capabilities that facilitate major shifts in diet. How such anatomical changes relate to ecological niche occupation across sizes is not well understood. In this study, we focused on the effects of ontogenetic changes on the force-generating mechanisms for jaw closure to assess the impacts of scaling on feeding biomechanics. We developed dissection-based, musculoskeletal models of maximum bite-force generation throughout ontogeny and compared and tested their veracity with data from an A. mississippiensis developmental series, for which bite forces were directly measured. Through examinations of the scaling patterns within the parameters of our models, we discuss how muscle pennation and positive allometry in the American alligator jaw adductor system facilitate capture strategies and oral processing of prey, and contribute to developmental niche shifts in this large-bodied taxon. On the basis of conservation of the crocodylian jaw adductor system, we argue that our findings are broadly applicable to crown Crocodylia and reflect an important, but often overlooked, aspect of the crocodylian feeding ecomorphology: littoral, sit-and-wait predation is enhanced by posteroventrally displaced, exceptionally large, and forceful ventral pterygoideus muscles, in particular. Future studies on the ontogeny and evolution of feeding in crocodylians should not neglect the functional and ecological implications of these muscles' contributions to diet.

AB - Crocodylians undergo substantial increases in size during ontogeny. The American alligator, Alligator mississippiensis, in particular traverses nearly four orders of body mass between hatching and senescence. Accompanying such changes are modifications in rostrodental morphology and feeding capabilities that facilitate major shifts in diet. How such anatomical changes relate to ecological niche occupation across sizes is not well understood. In this study, we focused on the effects of ontogenetic changes on the force-generating mechanisms for jaw closure to assess the impacts of scaling on feeding biomechanics. We developed dissection-based, musculoskeletal models of maximum bite-force generation throughout ontogeny and compared and tested their veracity with data from an A. mississippiensis developmental series, for which bite forces were directly measured. Through examinations of the scaling patterns within the parameters of our models, we discuss how muscle pennation and positive allometry in the American alligator jaw adductor system facilitate capture strategies and oral processing of prey, and contribute to developmental niche shifts in this large-bodied taxon. On the basis of conservation of the crocodylian jaw adductor system, we argue that our findings are broadly applicable to crown Crocodylia and reflect an important, but often overlooked, aspect of the crocodylian feeding ecomorphology: littoral, sit-and-wait predation is enhanced by posteroventrally displaced, exceptionally large, and forceful ventral pterygoideus muscles, in particular. Future studies on the ontogeny and evolution of feeding in crocodylians should not neglect the functional and ecological implications of these muscles' contributions to diet.

KW - Crocodylia

KW - biomechanics

KW - bite force

KW - ecomorphology

KW - feeding ecology

KW - ontogeny

KW - pennation

KW - scaling

UR - http://www.scopus.com/inward/record.url?scp=84971505173&partnerID=8YFLogxK

U2 - 10.1111/jzo.12349

DO - 10.1111/jzo.12349

M3 - Article

AN - SCOPUS:84971505173

VL - 299

SP - 229

EP - 238

JO - Journal of Zoology

JF - Journal of Zoology

SN - 0952-8369

IS - 4

ER -