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
Cretaceous Dawn Cretaceous Dawn Cretaceous Dawn is a science-fiction novel by sibling scientists Lisa M. Graziano and Michael S. A. Graziano, published in 2008 by Leapfrog Press (initially published as 'Hell Creek: 65 Million Years in the Past, the Journey Begins' under Trafford Publishing in 2006. The book contains 304 pages. Its story is set to a modern time and also to the prehistory of 65 million years ago (at the end of the Cretaceous era). It starts in the physics laboratory, where long-extinct beetles start to appear. Four people and a dog are then hurled 65 million years through the deep