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Triassic-Jurassic Extinction Event
At the beginning of the Jurassic Period, there occured a massive extinction event due to extreme climate change, meteor strikes, and lots of sulfur dioxide and carbon dioxide introduced into the environment. -
Beginning of Jurassic Period
The Jurassic Period began immediately after the Triassic-Jurassic Extinction Event. -
Hettangian Age
The Hettangian Age was the first age in the Jurassic Period. In this period, the Ichthyosaurus, the Abrictosaurus, the Heterodontosaurus, the Scelidosaurus, the Macroplata, and the Rhomaleosaurus lived on Pangaea. -
Sinemurian Age
The Sinemurian Epoch is the second earliest stage in the Jurassic Period. The Icthyosaurus, the Abrictosaurus, the Scelidosaurus, the Plesiosaurus, and the Dilophosaurus lived in this epoch. -
Pliensbachian Age
The Pliensbachian Age was the third earliest stage in the Jurassic Period. The Crylophosaurus, and the Dilophosaurus lived during this Epoch. This Epoch ended with the Toarcian Turnover or the Early Jurassic Extinction Event. -
Toarcian Age
The Toarcian Age is the last stage in the Early Jurassic Epoch. It is considered to be the end Epoch of the "Early Jurassic Period". It began with the Toarcian Turnover, a large scale extinction event that killed many species. The creatures alive during the Toarcian Epoch were the Plesiosaurus, the Rhomaleosaurus, the Barapasaurus, and the Pelagosaurus. -
Aalenian Age
The Aalenian Age marks the beginning of the "Middle Jurassic Period". The creatures existing during this period were the Belemnites, early squid-like creatures, and many forms of ammonite genera, early nautilus-like creatures. -
Bajocian Age
In the Bajocian Age, large finned crocodile-like fish, such as the Metriorhynchus (as pictured), thrived. They hunted cephlapods and marine mammals. In addition, dinosaurs continued evolving to larger, more powerful reptiles. Nautiloids and belemnites were also growing in population. -
Bathonian Age
The Bathonian Age was the first major Jurassic stage where dinosaurs became the dominant land mammals. The Huayangosaurus (as pictured) was one of the first to evolve. It was an hervibore and it had a scaly back for defense. The Shunosaurus and the Agilisaurus were other herbivores that evolved in this period. The Tianchisaurus was the only major carnivore in this epoch. -
Callovian Age
The Callovian Age was the last stage in the Middle Jurassic epoch. Carniverous fish thrived, like the Liopleurodon and the Peloneustes, and they fed off fish and cephlapods. The Eustreptospondylus was the largest carnivorous dinosaur, and it mostly fed off smaller reptiles like the Huayangosaurus and large sauropods. Large neocoleoids (octopi) fed off crustaceans. -
Oxfordian Age
The Oxfordian Age marks the beginning of the Late Jurassic Epoch, the last epoch in the Jurassic Period. The Dinosaur population greatly increased, but most of the dinosaurs were still herbivores, like the Tuojiangosaurus and the Yinlong. Also, the Geosaurus dominated sea life. It fed off fish, cephlapods, octopi, and marine mammals. Its close relative was the Metriorhynchus, which continued to evolve like it had the entire period. Produvalia (belemnite) and nautiloids continued to evolve. -
Kimmeridgian Age
The continuous Jurassic evolution continued through the Kimmeridgian Age. The Archaeopteryx was the oldest known flying creature and it recognized as the first bird ever. Plesiosaurs (sea monsters) and Ornithopods (herbivore dinosaurs) continued to develop different mechanisms to stay protected from the growing carnivorous theropod population. One example is the Othnielosaurus, which became more agile with its hunched back. Sauropods and the Dakosaurus are examples of creatures that evolved. -
Tithonian Age
The Tithonian Age was the last stage of the Jurassic Period. The Cretaceous Period followed, and it was marked by the warming climate. In the Tithonian, the Allosaurus and the Archaeopteryx were the most common carniverous animals. Birds, scaled reptiles, long-necked dinosaurs, swimming crocodile-fish, cephlopods, octopi, and belemnites were the most common creatures by the end of the Jurassic Period. -
End of Jurassic Period
No major extinctions involved; the end of the period is defined by selected locations.