Cretaceous–Paleogene boundary Cretaceous–Paleogene boundary The Cretaceous–Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K-T) boundary, is a geological signature, usually a thin band of rock. "K", the first letter of the German word "Kreide" (chalk), is the traditional abbreviation for the Cretaceous Period and "Pg" is the abbreviation for the Paleogene Period. The K–Pg boundary marks the end of the Cretaceous Period, the last period of the Mesozoic Era, and marks the beginning of the Paleogene Period, the first period of the Cenozoic Era. Its age is usually estimated at around 66 Ma (million years ago), with radiometric dating yielding a more
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 Despite its somewhat outdated view of dinosaurs, "The Age of Reptiles" is still notable for its historical and