There are a lot of dead turtles here in Magdalena Bay and in the adjacent Bahia Santa Maria. Dunno why. Maybe the shrimpers. They kill everything. Maybe the tuna seiners. There’s lots of tuna seiners here, and lots of turtles. Bound to be trouble.
We discussed the excellently thought-out turtle construction scheme earlier. In the comment section, Pender raised the possibility of a skin over the shell, but we hadn’t seen that yet.
Here is a dead turtle. The less interesting parts (from an engineering perspective) have been removed by a TA.
In close-up, we can clearly see the compression bone/ribs acting as the spokes in the wheel, and the roundular tension “tire” completing the structure. We can also see some lingering tissue binding the two together.
In this more recent mort, we can see that there is indeed a leather or membrane covering the entire shell, and that a tougher material (ligament, perhaps?) not only binds the tire to the spokes, but I’m sure also provides the flexibility required for effective oceanic maneuvering. Pender is vindicated.
However, here’s a remaining puzzle. Turtle shells are prized as ornaments, but the color and sheen comes completely from a skin that quickly degrades. Are decorative turtle shells painted by mischievous malfeasants? More research is required.