Which snakes unhinge their jaws

In August , scientists documented a boa constrictor eating a howler monkey. In March , an African rock python swallowed a spotted hyena. That same month, a foot-long Burmese python killed and consumed a farmer whole.

And a woman in Indonesia befell the same fate in June Reports also document snakes swallowing everything from adult deer to alligators and even cows. So, what enables them to gobble such large entrees? Gregory, a biology professor at the University of Victoria. The two lower jaws move independently of one another see image , Gregory said. The quadrate bone is not rigidly attached to the skull, but articulates with the skull at one end and is therefore freely moving.

However, in file snakes and most other advanced snakes, including all venomous species, an elongated quadrate does the same job. Early snakes swallowing large prey would have been a ready target for evolutionary fine-tuning — by just lengthening either of the two skull bones that suspend the lower jaw they could greatly expand their gape and therefore swallow bigger prey.

It seems the ancestors of pythons enlarged one of these bones, and the ancestors of file snakes the other. Actually, similar changes happen during the growth of all animals, including us. By slightly tinkering with the amount and direction of such growth-related proportional changes, evolution can relatively quickly sculpt new adult body shapes without a lot of other genetic change.

By including baby snakes as well as adults in our study we were able to see that the mouths of big-jawed snakes get proportionately as well as absolutely larger as they grow. We noticed that baby pythons have a short supratemporal bone and a jaw joint that is level with the back of the skull. However, the supratemporal grows faster than the rest of the skull, so by adulthood the jaw joint has been carried backwards well behind the skull.

Thus, a minor increase in the growth rate of this bone leads to a radically different adult skull. Either way, a slight alteration in growth patterns results in a major change in adult shape and function. Snakes are one of the most formidable success stories of evolution, having survived for more than million years, sailing through the mass extinction that wiped out all non-avian dinosaurs. The snake then moves his spine behind the food, which causes his ribs to push in on the food, effectively pushing the food further down his throat into his stomach.

With a professional background in gardening, landscapes, pests and natural ecosystems, Jasey Kelly has been sharing her knowledge through writing since and has served as an expert writer in these fields.

Kelly's background also includes childcare, and animal rescue and care. By using the site, you agree to the uses of cookies and other technology as outlined in our Policy, and to our Terms of Use. Feeding Facts Most people are aware that snakes swallow their food whole as opposed to taking bites, but how they do this is still a mystery to some. Extra Bones The joint between your jaw and your skull is one of the pivotal features that allows you to open your mouth.