|Dorsal (left) and ventral views of the holotype skull of Ocepechelon bouyai. From Bardet et. al, 2013.|
All we know of the turtle thus far is its skull, but skulls are often the most revealing fossils, especially when they're as outlandish as that of Ocepechelon. Measuring 70cm long, it is clear that this turtle was a giant, definitely one of the largest to ever live. But what makes the skull particularly unique is its shape and, thus, its function: although it is very long, it tapers into a very slender and narrow mouth, the opening of which measures only 6cm in diameter.
|Lateral view of the holotype skull of Ocepechelon. From Bardet et. al, 2013.|
This pipe-like tube of a mouth is reminiscent of animals which aren't even slightly related to turtles, namely beaked whales*, pipefish and seahorses. All of these animals have tiny mouths when compared to the size of their heads, and all feed on tiny prey using suction as their primary hunting method. It would appear that, without any adaptations to pin down, grasp, or pierce prey items, Ocepechelon was also a suction-feeder, spending its time close to the surface of the open Cretaceous seas, sucking in jellies and cephalopods which lingered nearby.
*Also strangely similar to whales is the position of Ocepechelon's nostrils: they are located far back on the skull, as far as turtles go. This also suggests it spent more time at the surface of the water.
|Ocepechelon bouyai, in the flesh. I... Uh, I don't really know... What to say. It's just a weird, weird creature.|
Bardet, Nathalie, Nour-Eddine Jalil, France de Lapparent de Broin, Damien Germain, Olivier Lambert, and Mbarek Amaghzaz. 2013. “A Giant Chelonioid Turtle from the Late Cretaceous of Morocco with a Suction Feeding Apparatus Unique Among Tetrapods.” PLoS ONE 8 (7) (July 11): e63586. doi:10.1371/journal.pone.0063586.
For more on giant, weird turtles, see...