Jurassic Jurassic The Jurassic (; from Jura Mountains) was a geologic period and system that spanned 56 million years from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period Mya. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles. The start of the period was marked by the major Triassic–Jurassic extinction event. Two other extinction events occurred during the period: the Pliensbachian-Toarcian extinction in the Early Jurassic, and the Tithonian event at the end; however, neither event ranks among the "Big Five" mass extinctions. The
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