The term "Jurassic" refers to a geological period that lasted from about 201 to 145 million years ago. It is the second period of the Mesozoic Era, following the Triassic and preceding the Cretaceous. The Jurassic is known for its diverse range of dinosaurs, including famous species like Brachiosaurus and Stegosaurus, as well as the emergence of early birds and mammals. During the Jurassic period, the Earth's continents were positioned differently than today, leading to a warm climate and lush vegetation. This environment supported vast forests and numerous marine life forms, including ammonites and ichthyosaurs. The Jurassic is significant for understanding the evolution of life on Earth and the development of ecosystems.