What are some chalk organisms?

Cretaceous period is a geological period that stretches from 145.5 to 65.5 million years. With a total of 80 million years, chalk has been the longest geological periods over the last 542 million years. He is known for dominated by dinosaurs and other large reptiles such as pterosaurs (winged reptiles), Mosasaur, Plesiosaurs, Ichthyosaurs and Plosaurs (all sea reptiles). The mammals were present as little gadgets at night, just like some giant amphibians who survived geographical insulation. Birds began to diversify and compete with pterosaurs for the sky.

During the chalk, the climate was warm and the sea levels were high. Much of this heat came from abundant volcanic activity, which released a large amount of carbon glass gas oxide into the atmosphere. Forests, made of conifers and/or cycads, covered the planet, including the South Pole. Much of North America was flooded with the Epicontinental Sea called the Western Interior Seaway and the water covered most of the modern India, Africa and Europe.Because Australia was still associated with Antarctica, there was no freezing circumpolar current and the Antarctic continent was warm and fresh.

Dinosaurs were various, especially at the very end of the period, and included Ceratopsians such as Triceratops , strongly armored ankylosaurs, gigant Sanuropos, dimensioned Hervopory, dimensioned playroom Hertivore Ornithopods, small, feathered dinosaurs and many others. Earth's vertebrate biomass was huge, probably more than twice today. If the dinosaurs were not erased at the end of the chalk, they would diversify even more and create other new forms.

The sea was occupied and dominated by the usual marine plasimi: Plesiosaurs and Plosaurs. Ichthyosaurs lived all over the chart and extinct about 25 million years before the dinosaurs did. Were among the only oneme with the main groups of reptiles that have died out in the middle of chalk and not in the event of a mass extinction at the end. At about the same time as the ichthyosaurs disappeared, a large snake of sea reptiles called Mosasaur has developed and matured up to 17.5 m (57 ft) in length, among the largest sea reptiles of all time.

65.5 million years ago, a massive asteroid hit the ground, caused magma rain, blocked the sun with dust, and killed almost all animals discussed in this article. The main groups of vertebrates that survived were birds, mammals, crocodiles and of course fish and sharks.