Piedmont Governor’s School student Zach Turman is doing a project on quantifying shark bite marks on the ribs of the Carmel Church baleen whale “Sinistra”. This whale was heavily scavenged by sharks, and he’s finding tons of bites. However, he also has been turning up other unusual marks that, so far, we haven’t been able to identify.
First are several small, circular depressions. These are vaguely similar to scars left on shells by the snail Crepidula, but these are much smaller and more perfectly circular. There are similar, but larger, marks on the sperm whale jaw we just finished preparing.
The second feature is a tiny, segmented linear feature that runs along the edge of one of the ribs. Here’s the whole structure (width of image ~ 1.5 cm):
This structure may be partly in the bone and partly in the sediment, although most of it appears to be in the bone. It is smaller than the points of any of the prep tools we use in our lab or in the field, so it’s not something we caused. It looks rather like the cross section of a spiral structure, so I’m wondering if it’s some type of spiral burrow.
At any rate, we’re still trying to figure out what these are, so if you have any ideas feel free to speculate in the comments.