My coauthor Haruka Ito and I are pleased to announce the publication of our new article in the
Journal of Experimental Biology, “Whale jaw joint is a shock absorber.”
https://jeb.biologists.org/content/223/7/jeb224642
Abstract:
The non-synovial temporomandibular jaw joint of rorqual whales is presumed to withstand intense stresses when huge volumes of water are engulfed during lunge feeding. Examination and manipulation
of TMJs in fresh carcasses, plus CT scans and field/lab mechanical testing of excised tissue blocks, reveals that the TMJ’s fibrocartilage pad fully and quickly rebounds after shrinking up to 68-88% in compression (by axis) and stretching 176-230%. It is more
extensible along the mediolateral axis and less extensible dorsoventrally, but mostly isotropic, with collagen and elastin fibers running in all directions. The rorqual TMJ pad compresses as gape increases. Its stiffness is hypothesized to damp acceleration,
whereas its elasticity is hypothesized to absorb shock during engulfment; to allow for rotation or other jaw motion during gape opening/closure; and to aid in returning jaws to their closed position during filtration via elastic recoil with conversion of stored
potential energy into kinetic energy.
The article can be found on the JEB website, or contact me if interested in receiving a copy.
Best regards,
Alex
_______________________________
Alexander J. Werth, Ph.D.
Trinkle Professor of Biology
Hampden-Sydney College
Box 162, Hampden-Sydney, VA 23943
434-223-6326, fax 434-223-6374