At the SAVP meeting last June Brian Beatty and I presented a paper on the Carmel Church whale’s broken left jaw, in which we suggested that the injury was caused by a head-on collision rather than a bite or a blow from the side. Here is a close-up of the break, in medial view:
We separated the broken halves in the X-ray image to keep things clear. One interesting feature is that the original bottom edge of the dentary is visible, with the bone callus plated under it. We believe that the irregular dark patches on each side of the break are pits in the bone caused by abscesses. The dark band running through the middle of the dentary is the mandibular canal; the dark lines leading diagonally up from the mandibular canal are channels leading to nutrient foramina. These carried nerves and blood vessels that supplied the lips and skin.
The image at the top shows the same break in dorsal view, with the medial side at the bottom. Again, the bony calluses are visible over the original bone surface. One noteworthy feature is the piece of bone that is pealed back medially along the break (the part that is pointing down at an odd angle). This piece of bone is imbedded in a callus, so it’s part of the original break, rather than something that occurred after burial.
We’re still studying these images, but so far the X-rays are consistent with our original interpretation of the injury. Thanks to Brosville Animal Clinic for humoring us on our unusual request.