A shrew-like primitive mammal that inhabited China 165 million years ago represents a milestone in mammalian evolution, scientists said on Thursday, boasting a key anatomical trait in its throat that helped usher in the era of polite table manners.
Scientists described an exquisitely preserved Jurassic Period fossil from Inner Mongolia of a furry critter called Microdocodon gracilis. It was a lightly built, long-tailed, insect-eating tree-dweller roughly 5 inches (14 cm) in length that lived in a warm lakeshore environment alongside feathered dinosaurs and flying reptiles called pterosaurs.
Before Microdocodon, land vertebrates including amphibians, reptiles and predecessors to the mammalian lineage had resorted to gulping large chunks of food or swallowing prey whole, as crocodiles do today, relying largely on jaw strength or gravity to guide the meal down the throat. A revolutionary change present in Microdocodon's throat allowed for more finesse in muscle-powered swallowing and, thus, genteel dining.