A flexible bone that helps mammals chew dates back to the Jurassic Period
The structure may have helped give rise to the Age of Mammals, a new fossil suggests
![Microdocodon gracilis fossil](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2019/07/071719_cg_mammal-chewing_feat.jpg?fit=1030%2C580&ssl=1)
JURASSIC CHEWER This fossil of the shrew-sized mammal ancestor Microdocodon gracilis, which lived about 165 million years ago, reveals that the shape of the hyoid, a flexible bone that aids in chewing, is similar to that of modern mammals.
Z.-X. Luo/Univ. of Chicago