NPR did a story about this recently https://www.npr.org/2019/06/08/730898366/checking-facts-in-n...
One of my senior professors used to say that during his school days, in one of their text books, it was mentioned that animals move their upper jaw when chewing food.
NPR did a story about this recently https://www.npr.org/2019/06/08/730898366/checking-facts-in-n...