Following the last article about the end of the Mesozoic Era, it is time we move on to the Cenozoic Era. It is the era we currently live in and the last period is still ongoing.
Recovering From The Mass Extinction
The Cretaceous-Paleogene extinction event wiped the major group in the Earth’s ecosystem- dinosaurs. They left behind a lot of empty geological niches. In the beginning, minor groups, that survived the extinction, started slowly filling those niches. When the climate became more hospitable, one of the groups took over dinosaurs’ place in the Earth’s ecology, being the new group occupying most of the ecological niches. That group was mammals and their reign lasts until today. Parallel to mammals, the only remaining dinosaur group also developed fast. Birds, which appeared in the Cretaceous, started to take over the place of pterosaurs, as the rulers of air. So-called ‘terror birds’ were larger than humans and were incredibly good predators.
Division of the Cenozoic
There were many controversies and discussions about the proper division of the Cenozoic Era. Finally, scientists concluded and divided the Cenozoic into three periods. First of all, the Paleogene spans from the extinction of dinosaurs and we divide it into three epochs. Those are Paleocene, Eocene, and Oligocene. The division of periods is quite common in the Cenozoic because it helps us navigate through the most recent changes in the history of life. After the Paleogene comes Neogene, featuring two epochs: the Miocene and the Pliocene. Finally, comes our current period- the Quarternary. It is the shortest period of the Phanerozoic, but it comes with many important changes. We divide it into the Pleistocene and the Holocene. The Holocene is the epoch we currently live in and it will be the last one we discuss.
Major Evidence from the Cenozoic Era
There are many important pieces of evidence from the Cenozoic Era because we can still observe it’s organisms and many other traces. Long lakes, valleys, and rivers can be evidence for the glaciation events. Mountains, like the Himalayas, prove the collisions of great landmasses. Observing animals on different continents using the biogeographical methods helps us understand how organisms adapted to certain conditions and evolved.
Despite mammals we can still observe, there are also many strange fossils of extinct organisms. For example, the ‘hell pigs’ – Entelodonts were pig-like animals, eating both plants and hunting other organisms. They lived in North America and Eurasia and went extinct about 16 million years ago. Despite mammals, there are almost twice as many species of birds. Snakes and other modern reptiles and amphibians also developed, however, there are fossils of extinct ones too. On the plant side, grass appeared in the Cenozoic and somehow directed the evolution of all organisms feeding on it.
I hope, that the article introduced you to the Cenozoic Era. If you enjoyed it, please share it with family and friends. We are now in the last phase of The History of Life Series. In the next ones, we will be discussing it’s periods, starting with the Paleogene. Until then, if you have any questions, feel free to contact me using the contact form below or my email address. I hope you are enjoying this series.