Is there a clear line between the Jurassic and Cretaceous?

Not really, in ecological terms. The transition was gradual. Some species that started in the Late Jurassic continued into the Early Cretaceous, while new groups were slowly emerging.

Home/Prehistoric Periods/Late Jurassic-Early Cretaceous

Late Jurassic to Early Cretaceous

163-100 million years ago

The transition from the Jurassic to the Cretaceous was a pivotal time for dinosaur evolution. Many of the iconic Jurassic giants were giving way to new forms, flowering plants were beginning to spread, and the continents were continuing to drift apart, isolating dinosaur populations and driving new species to evolve.

Fun Facts

✓The Jurassic-Cretaceous boundary was once considered a major extinction event, but modern research shows it was more of a gradual transition.
✓Flowering plants began spreading during this transition, eventually replacing the ferns and conifers that dominated Jurassic landscapes.
✓Continental drift was separating what had been connected landmasses, isolating dinosaur populations.

Questions About the Late Jurassic-Early Cretaceous

Other Prehistoric Periods

Triassic Late Triassic Middle Triassic Jurassic Early Jurassic Middle Jurassic Late Jurassic Middle-Late Jurassic View all periods →