Cretaceous–Paleogene extinction event Cretaceous–Paleogene extinction event The Cretaceous–Paleogene (K–Pg) extinction event, also known as the Cretaceous–Tertiary (K–T) extinction, was a sudden mass extinction of some three-quarters of the plant and animal species on Earth, approximately 66 million years ago. With the exception of some ectothermic species such as the leatherback sea turtle and crocodiles, no tetrapods weighing more than survived. It marked the end of the Cretaceous period and with it, the entire Mesozoic Era, opening the Cenozoic Era that continues today. In the geologic record, the K–Pg event is marked by a thin layer of sediment called the K–Pg boundary, which can
The Age of Reptiles the mural's beginning to the end of the Cretaceous period, 65 million years ago. Each period's length on the mural is proportional to the period's length in geologic time. Each period of time is divided by large trees in the foreground. Animal species are in bold. Devonian Carboniferous Permian Triassic Jurassic Cretaceous "The Age of Reptiles" won Zallinger several awards. Zallinger was awarded with a Pulitzer Fellowship in Art in 1949, and the painting was featured as a postage stamp in 1970. Despite its somewhat outdated view of dinosaurs, "The Age of Reptiles" is still notable for its historical and