WIKIMEDIA, STEVEN JOHNSON
Chewing is usually regarded as a uniquely mammalian trait. But researchers from the University of Toronto and the University of Washington have now added stingrays to the list of animals that can chew, capturing video of the ocellate river stingray (Potamotrygon motoro) as it crushes and tears prey with its jaws. The team published its results in Proceedings of the Royal Society B this week (September 14).
This stingray feeds on insects, which pose a challenge to potential predators because of the preys’ chitinous exoskeletons. Chitin is a tough, pliable substance, most effectively broken down with a tearing motion, which is what chewing allows the stingray to do, study coauthor Matthew Kolmann of University of Toronto told National Geographic’s Not Exactly Rocket Science.
“What I ...
