Evolution - From Dinosaurs to Mammals

MESOZOIC Duration: 150 million years, it is the Age of reptiles, which dominate sovereigns in all the eco-systems of the planet. The marine plants continued their development, and all the forms that are known today arose, the terrestrial ones reached great height, which constitutes one of the biological facts of greater significance in this era. The conifers, the cicadas and ginkgoales appeared; which have reached our days with numerous species. The petrified forests of Arizona are formed. At the end of the Era, in the Cretaceous, the first plants with flowers were formed: the angiosperms. A great variety of fertilizing insects arise. Among the animal fossils it can be observed that many of the invertebrates have forms similar to the present ones, as happens with corals; However among the mollusks there were very strange and large forms, such as ammonites. The echinoderms also abounded. The bony fish appeared at the beginning of the era, while the primitive amphibians were replaced by the current anurans and salamanders. The great Pangea continent begins to divide into two main continental masses separated by seas: Gondwana to the south and Laurasia to the north. The vegetation of the meadows springs up: the grass. The climate at the beginning is temperate and dry with a tendency to gradually increase until it becomes tropical. We divided the Secondary Era into three periods: TRIASSIC, JURASSIC and CRETACEOUS. 215.000.000- Begins the period TRIASSIC ...