Neither a dog nor a devil

A remarkable discovery has been made in China: the largest known mammal of the Mesozoic era, Reponomamus giganticus, which lived around 130 million years ago. Resembling a large dog, this carnivorous mammal resembled modern Tasmanian devils and preyed on young dinosaurs. Its impressive skeleton, with its well-preserved bones, also contained traces of its diet, including the remains of a dinosaur called Psittacosaurus. This find sheds new light on the evolution of mammals during the age of reptile dominance.

The largest known mammal of the Mesozoic Era (the Mesozoic: the era divided into the Cretaceous, Jurassic, and Triassic periods) has been discovered in China. Dating from about 130 million years ago (early Cretaceous), Reponomamus giganticus, the size of a large dog, is a unique specimen. During the first 160 million years of the Mesozoic Era, most mammals were the size of small rodents. They are described as small and insectivorous, nocturnal out of fear of numerous reptilian predators—and, without exaggeration, monsters.