Jurassic

Definition

The Jurassic is a geological period that lasted from about 201 to 145 million years ago, marking the middle segment of the Mesozoic Era. This period is significant for its warm climate, which supported lush vegetation and diverse ecosystems, including the rise of dinosaurs as dominant terrestrial vertebrates. The Jurassic also saw the development of early birds and mammals, setting the stage for future evolutionary paths.

5 Must Know Facts For Your Next Test

1. The Jurassic period is divided into three epochs: Early Jurassic, Middle Jurassic, and Late Jurassic, each marked by distinct geological and biological developments.
2. During the Jurassic, the climate was generally warm and humid, resulting in vast forests and a variety of plant life that supported large herbivorous dinosaurs.
3. Famous dinosaur species such as Brachiosaurus and Stegosaurus thrived during this period, showcasing remarkable diversity in size and shape.
4. The first true birds, like Archaeopteryx, appeared in the Late Jurassic, indicating significant evolutionary advancements from theropod dinosaurs.
5. Marine life flourished during the Jurassic as well, with the presence of large marine reptiles like Plesiosaurs and abundant ammonites in oceans that covered much of the Earth.

Review Questions

• How did the breakup of Pangaea during the Jurassic influence global biodiversity?
  • The breakup of Pangaea during the Jurassic had a profound impact on global biodiversity as it led to geographical isolation of species. This isolation allowed for adaptive radiation, where species evolved in response to their specific environments. As landmasses drifted apart, different groups of dinosaurs adapted to various climates and habitats, resulting in a rich diversity of species across different continents.
• Discuss the significance of climate conditions during the Jurassic in relation to dinosaur evolution.
  • The warm and humid climate of the Jurassic was crucial for dinosaur evolution as it supported diverse ecosystems filled with lush vegetation. This abundance of plant life provided ample food resources for herbivorous dinosaurs, which in turn supported large carnivorous species. The favorable climate conditions allowed dinosaurs to thrive and diversify into numerous forms, leading to some of the most iconic species known today.
• Evaluate the impact of the Jurassic period on subsequent geological and biological developments in Earth's history.
  • The Jurassic period laid important groundwork for future geological and biological developments by fostering an environment rich in biodiversity and dynamic ecosystems. The evolutionary advancements seen during this time, such as the emergence of early birds and mammals from theropod ancestors, set evolutionary trajectories that would influence later periods. Additionally, geological changes such as continental drift reshaped Earth’s landscapes and climates, affecting life forms for millions of years to come.

Related terms

Mesozoic Era: The Mesozoic Era is known as the Age of Reptiles, spanning from about 252 to 66 million years ago, and includes the Triassic, Jurassic, and Cretaceous periods.

Pangaea: Pangaea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras, which began to break apart during the Jurassic, leading to the formation of modern continents.

Dinosaurs: Dinosaurs were a diverse group of reptiles that emerged during the Triassic and became the dominant land animals during the Jurassic period.