| large mesozoic mammals fed on young dinosaurs. | mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs. the largest known mesozoic mammal represented by substantially complete remains is repenomamus robustus, a triconodont mammal from the lower cretaceous of liaoning, china. an adult individual of r. robustus was the size of a virginia opossum. here we report a new species of the genus, represented by a skeleton with most of the skull and p ... | 2005 | 15650737 |