Cenozoic

The K-Pg mass extinction event marked the end of the Cretaceous Period, but also the end of the Mesozoic Era. During the Cenozoic, life would recover and the Earth would be replenished by the species that survived. Like we saw following the Great Dying at the end of the Permian, life would be forever changed after the K-Pg mass extinction event and the ecological niches once dominated by reptiles would be taken over by birds, mammals, and fish.