Sail on their back, which is an extension of their spine. This piece of sail may be used to attract the opposite sex, or it may be used to regulate body temperature - turning the sail to absorb heat when it faces the sun, and dissipating heat when it is not exposed to sunlight. Prehistoric_12 250 million years ago, a giant iguana had a sail on its back, perhaps to attract mates or to regulate its body temperature. In the ocean, there are some large sharks up to 12 meters long. Their mouths have a very strange structure. Their jaws have a round bone with sharp teeth. Cut in half.
Prehistoric_2 In the ocean 250 photo color correction services million years ago, there were some large sharks up to 12 meters long, their mouths had a structure like a sawing machine, and they cut their prey in half. During this period, the earth experienced strong crustal movement, and volcanic activity released a large amount of sulfur oxides into the atmosphere, blocking sunlight, making it difficult for plants to photosynthesize, and their numbers declined, which in turn affected herbivores and carnivores. This mass extinction wiped out 85% of the species on earth, including the long-lived trilobites, which is the largest mass extinction event in history.
Some four-legged vertebrates have survived and have continued to follow the evolutionary pace. The advent of the age of dinosaurs The earth 200 million years ago was a reptile world, and the sea, land or sky were covered with their footprints. The top predators in the sea were the Ichthyosaurs, reptiles that returned to the sea from land to eat fish and squid. On land, there are armored herbivores, always on guard against the attack of small primitive dinosaurs. Pterosaurs appeared in the air, flapping their wings and soaring into the sky. Volcanic activity has become more frequent, and 70% of species have lost the battle of nature. Small dinosaurs survived, and it took only a short time for them to