Middle Jurassic facts for kids
The Middle Jurassic was a time long, long ago, part of the Jurassic period. It started about 174.1 million years ago. It ended around 163.5 million years ago. This was a very important time for Earth and its living things.
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Earth's Changing Face
During the Middle Jurassic, the supercontinent Pangaea began to break apart. It slowly split into two big landmasses: Laurasia in the north and Gondwana in the south. This splitting created the Atlantic Ocean. Huge movements in Earth's crust, called tectonic activity, also closed an ancient ocean called the Paleo-Tethys Ocean. On the west coast of North America, these movements continued to build the early Rocky Mountains.
Amazing Animals and Plants of the Middle Jurassic
Life in the Oceans
In the Middle Jurassic oceans, many sea creatures thrived. Ammonites and bivalves were very common. Ichthyosaurs, which were like fish-shaped reptiles, were still around but less diverse. A new type of crocodilian, similar to modern crocodiles, appeared for the first time.
Plesiosaurs, long-necked marine reptiles, became common during this period. The top predators of the sea were the pliosaurs. These powerful hunters grew to be as big as killer whales or even larger! Famous examples include Pliosaurus and Liopleurodon.
Dinosaurs and Other Land Animals
On land, many new types of dinosaurs evolved. One early sauropod (a long-necked, plant-eating dinosaur) was Cetiosaurus. Its fossils were first found in England in the mid-1800s.
Cetiosaurus lived in areas with floodplains and open woodlands. Other large dinosaurs, like brachiosaurs and the meat-eating Megalosaurus, also lived in these environments.
Small, mammal-like reptiles called cynodont therapsids also lived alongside the dinosaurs. Most were only the size of a shrew. None grew larger than a badger. One group of cynodonts, the Trithelodonts, became rare and eventually died out by the end of this epoch. However, the Tritylodonts were still common. It was during this time that "true" mammals evolved from a group of cynodonts.
Plants of the Middle Jurassic
Conifers, like modern pine trees, were the most common plants in the Middle Jurassic. Other plants, such as ginkgoes, cycads, and ferns, were also widespread. These plants provided food for the huge plant-eating dinosaurs.
Related pages
Images for kids
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Middle Jurassic strata of the San Rafael Group, Colorado Plateau.
See also
In Spanish: Jurásico Medio para niños
