Adaptive Radiation in Mammals | Vertebrates | Chordata | Zoology

During Mesozoic era, the age of reptiles (dinosaurs), mammals were small, generalised and rare. By the end of Mesozoic or beginning of Coenozoic, the dinosaurs vanished and mammals suddenly expanded into varied evolutionary patterns. Early in Cretaceous period, placental mammals became distinct from marsupials. During Eocene and Oligocene, most of the orders of mammals originated moving into habitats and ecological [...]