Ontogeny of feeding function in the gray short-tailed opossum Monodelphis domestica: Empirical support for the constrained model of jaw biomechanics

Elicia N. Thompson, Audrone R. Biknevicius, Rebecca Z. German

Research output: Contribution to journalArticlepeer-review

Abstract

The constrained model of masticatory function enables specific predictions of bite force potentials in skulls of differing craniodental configurations. In this study, empirical support for the constrained model is provided using maximum voluntary bite force data along Region I and II of the jaws of gray short-tailed opossums Monodelphis domestica. Then, growth series of M. domestica are used to assess how bite force potential changes with growth by evaluating craniodental changes using longitudinal sets of dorsoventral radiographs and by assessing maximal bite force potential at the Region I-II boundary of the jaw in juveniles (aged 70-80 days) and adults. Our findings show that, while juveniles and adults alike enclose at least three molariform teeth within Region II (the area of highest bite force potential along the jaw), age-dependent elongation of the masticatory muscle resultant lever arm and narrowing of the palate relative to jaw length especially enhance the mechanical advantage of the adductor muscle resultant in adults. While maximal bite forces at the Region I-II boundary are absolutely greater in adults, these bite forces scale isometrically with body mass, which suggests that mass-specific forces exerted by jaw adductor muscles of larger (adult) opossums are disproportionately smaller than those exerted by smaller (juvenile) opossums.

Original languageEnglish (US)
Pages (from-to)923-932
Number of pages10
JournalJournal of Experimental Biology
Volume206
Issue number5
DOIs
StatePublished - Mar 2003
Externally publishedYes

Keywords

  • Bite force
  • Gray short-tailed opossum
  • Monodelphis domestica
  • Ontogeny

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Agricultural and Biological Sciences (miscellaneous)

Fingerprint Dive into the research topics of 'Ontogeny of feeding function in the gray short-tailed opossum Monodelphis domestica: Empirical support for the constrained model of jaw biomechanics'. Together they form a unique fingerprint.

Cite this