Jurassic Period 208 – 146 Million Years Ago

The Jurassic period was the middle period of the Mesozoic era. The name Jurassic comes from the Jura Mountains between France and Switzerland where the rocks formed during this period were first studied.

The world at this time showed that it was a more equable climate, forests of conifers and ferns began to develop, birds began to evolve from the dinosaurs and limestone and iron ore were deposited.

In the early Jurassic period the size of the dinosaurs increased steadily and eventually, towards the middle of the Jurassic period, the Prosauropods began to disappear. As they became extinct another species of dinosaur the Sauropods began to replace them. These animals thrived right through the remainder of the Jurassic and well into the early Cretaceous period

Sauropods like Diplodocus grew to about 30m in length, had massive bodies with extremely long necks and whip like tails and walked on all fours.

Diplodocus - A Jurassic Sauropod

Diplodocus

Yet even they were dwarfed by the really large Sauropods like Apatosaurus and Brachiosaurus who it is estimated weighed up to more than 20 of today’s elephants. It appears that it took between 10 to 20 years for them to reach their adult size and they could live for upwards of 70 years.

Allosaurus - Top carnivore of the Jurassic

Allosaurus Prints

The Stegosaurus was one of the first armoured dinosaurs covered in formidable plates running down it’s back whilst the Allosaurus could best be described as the lion equivalent of the Jurassic period.

Not only do we see giants on the land but we can also see giant marine reptiles Ichthyosaurs appearing in the seas. These marine reptiles developed through the Triassic and into the Jurassic where they resembled large dolphins.

As well as the Ichthyosaurs, the Jurassic also saw the rise of the long necked Plesiosaurs and short necked Pliosaurs. Pliosaurs like Lipleurodon were major predators in the Jurassic seas whilst Plesiosaurs tended to eat smaller fish and other small animals.

Dilophosaurus was a quick bipedal meat-eater from the early Jurassic

We also know that molluscs such as Ammonites were common as their fossils are found in Jurassic rocks.
Ready? Lets go to the Cretaceous Period