Good tidings and well-wishes, readers! I realize that this topic pertains more accurately to zoology than paleontology, however, since the two subjects are quite closely-related and this is a very fascinating concept, so I’ve decided to touch on it here.
After my last post, in which I briefly discussed Dr. Schwimmer’s theory that Deinosuchus likely engaged in heavily-chelonivorous (turtle-eating) habits, I did a bit of research on the subject of chelonivory in general, which leads me to Chris Mattison’s excellent book, “The new encyclopedia of snakes”. I must admit that I wasn’t expecting to find anything on the topic within the volume; after-all, snakes seem fantastically ill-equipped to dine on chelonians…their shells are too resilient to allow the creatures to become asphyxiated, which would mean that, in most cases, the animal would have to be swallowed whole, thus putting the consumer at risk from claw and beak damadge. However, Mattison points out that, as is almost invariably the case in nature, exceptions occur:
“Turtles must rate highly on the list of indigestible food items, but are not completely overlooked. Among the species eaten by snakes are musk turtles, a common snapping turtle, box turtle, two species of sliders (and baby American alligators) found in the stomachs of Cottonmouths, Agkistrodon piscivorous, and a hatchling hawksbill turtle was eaten by a Cuban ground snake, Alsophis cantherigerus. Less surprisingly, freshwater turtles, and caimans, are eaten by anacondas, Eunectes murinus, in South America.
These examples, in retrospect, aren’t particularly surprising. After-all, a venomous snake such as a cottonmouth would have no trouble immobilizing a small chelonian prior to consumption, hatchling hawksbills (like the infants of nearly all sea turtles) are vulnerable to predation, and, as Mattison notes, it’s not difficult to imagine a fully-grown anaconda could easily devour a small freshwater turtle even without the benefit of its hefty constrictive coils.
When one considers extant creatures, one tends to host some involuntary pejudices about the habits of certain beasts, after-all, who’d have thought a snake would eat a turtle? By the same logic, who’d suspect that herons would eat doves, lions would hunt giraffes and elephants, some pythons specialize in eating bats, and snapping turtles would eat other chelonians? However, all of these occurances have been documented, and thus, despite our initial disbelief, they’re irrefutably true. With this in mind, just how many prehistoric creatures had dietary habits we aren’t aware or even suspicious of? A few weeks ago, I described a hypothesis put forth by the gang at Sloth Central which argued that Megalonyx, the flat-footed giant ground sloth, may have been a part-time sanguivore (blood-eater). What other culinary oddities could have existed somewhere in the incomparably rich and diverse history of life on this planet? It’s a question we’ll probably never be able to answer, but nonetheless, it’s worth pondering.
May the fossil record (and the rest of natural world) continue to enchant us all.