A three dimensional free body analysis describing variation in the musculoskeletal configuration of the cynodont lower jaw

Evolution & Development
D A ReedT G H Diekwisch

Abstract

The evolution of the middle ear from the cynodont craniomandibular bones is one of the key mammalian innovations, and the mechanics underlying this anatomical transformation represents an intriguing paradox. Because the jaw joint of nonmammalian cynodonts was functionally coupled to the inner ear, auditory performance would favor low joint reaction forces. However, this could not be achieved at the expense of feeding performance, favoring high bite forces. The balance of these two seemingly incompatible performance criteria in the context of the morphological diversity of the cynodont lower jaw is poorly understood. Here we derive a series of equations using three dimensional free body analysis that describe the relationship between the orientation and position of the jaw elevator muscles, the position of the jaw articulation relative to the bite point, the joint reaction forces and the bite force in the lower jaw of the nonmammalian cynodont Probainognathus. These equations permit the effects of variation in each variable to be tested independently, yielding three terms that act to limit joint reaction forces without substantially impacting bite force: the reorientation of the resultant muscle force more vertically, shifting t...Continue Reading

References

May 1, 1979·Journal of Morphology·R E Druzinsky, W S Greaves
Dec 1, 1975·Journal of Morphology·E F Allin
May 1, 1970·Science·H R Barghusen, J A Hopson
Aug 1, 1966·American Zoologist·J A Hopson
Sep 1, 1980·American Journal of Physical Anthropology·S C Ward, S Molnar
May 6, 1999·American Journal of Physical Anthropology·M A Spencer
Jul 2, 2011·Integrative and Comparative Biology·Susan H WilliamsWilliam L Hylander
Jun 13, 2012·Journal of Anatomy·Neal AnthwalAbigail S Tucker
Aug 30, 2013·Proceedings. Biological Sciences·Marcello RutaMichael J Benton

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Citations

Aug 27, 2016·Frontiers in Zoology·Héctor E Ramírez-ChavesMatthew J Phillips
Nov 24, 2016·Biological Reviews of the Cambridge Philosophical Society·Stephan LautenschlagerEmily J Rayfield
Mar 23, 2017·Scientific Reports·David M Grossnickle
Sep 19, 2018·Nature·Stephan LautenschlagerEmily J Rayfield

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