The Turonian is a stage in the geological time scale that occurred during the Late Cretaceous period, approximately 93.9 to 89.8 million years ago. It is characterized by significant geological and biological changes, including the diversification of marine life and the appearance of new species of dinosaurs and ammonites. During the Turonian, the Earth's climate was generally warm, and sea levels were high, leading to widespread shallow seas. This period is important for understanding the evolution of marine ecosystems and the conditions that led to the later mass extinction events at the end of the Cretaceous.