Jurassic Period

The Jurassic Period longed for 56 million years between 201.3 and 145 million years ago. It was the second period of the Mesozoic Era, and followed the Triassic-Jurassic extinction event at the end of the Triassic Period, and took place before the Cretaceous Period.

At the beginning of the Jurassic Period, Pangea split into two separate parts: Laurasia (in the north, comprising Europe, Asia without India, and North America) and Gondwana (in the south, comprising Africa, South America, Antarctica, Australia, Arabia, and the Indian Subcontinent). These two main parts also started to broke up into smaller units.

Jurassic globe

The Earth's continents in the Jurassic Period, 155 mya.

Climate during the Jurassic was about 5 °C to 10 °C warmer than today, and there were approximately five times more carbon dioxide in the atmosphere, and probably the poles were not covered by ice caps. Instead, there grew forests, which had warm summers and cold, snowy winters. Continental climate shifted to more humid from the Permian dry, and those territories which were deserts during the Perm became thriving rainforests.

The flora in the Jurassic period was very different from the Permian vegetation, and conifers became the dominant elements in terrestrial flora. Besides them, ferns, Ginkgoales, Bennettitales, Gnetophytes and cycads were also significant in the vegetation. However, we do not know any fossils of flowering plants from the Jurassic.

During the Jurassic, marine reptile groups, like ichthyosaurs, plesiosaurs, and marine crocodyliformes, reached their highest diversity.

On land the dinosaurs became dominant. This was the golden age of the enormous, long-necked sauropods. Ornithischian herbivorous dinosaurs were also widely occurred, as well as large theropods. In the air pterosaurs were dominant, however, during the Late Jurassic the first feathered bird-like dinosaurs, like Archeopteryx, also evolved. Surviving thermospondyl amphibians and small mammals played only marginal role, however, these latter diversified extensively during the Jurassic.