The Cenozoic era is the third stage of the constitution of Planet Earth as we know it today, which spans from the early Paleocene (approximately 66.5 million years ago) to the present. During that period, the Earth underwent a long-term cooling period: this was largely due to the blocking of solar radiation.
Many geological events occur in this era, fundamental to the current structure of the Earth. India collided with Asia and Arabia collided with Eurasia, resulting in the closure of the Sea of Tethys. On the other hand, there are many animals that evolved over the course of the Cenozoic, developing until the present in the condition that they are known for.
- See also: Paleozoic era animals
Stages of the Cenozoic
There are five stages of the Cenozoic period, and in each of them there were events of a geological nature but also related to the formation of animal species:
- Paleocene . It is the one that has the definitive separation between Australia and Antarctica, and also that of the formation of the Norwegian Sea. Asia joins North America through the Bering Strait. In a period of abundant rain, some continental areas are flooded by rising waters, such as the Mediterranean Sea. The following animals were developed at that time:
- Marsupial mammals (small head, narrow snout, and reduced cranial cavity)
- Insectivores
- Lemurs
- Primates
- Rodents
- Creodonts
- Primitive hoofed animals.
- Eocene . I include the breakup of the supercontinent of Laurasia, where the mountain systems of the Alps and the Himalayas continued to rise: this was due to a movement of plates in which continuous and abundant basalt eruptions of northeast India and Siberia also took place. The weather was practically unchanged from the previous period. The following species developed there:
- Sea mammals
- Horse
- Camel
- Rhinoceros
- Squirrels
- Eagles
- Pelicans
- Quail
- Vultures
- Oligocene . It continues with the uplift of mountain ranges, and the remnants of the former supercontinent of Gondwana collided with Eurasia to the north, closing off the Tethys Sea and leaving the Mediterranean. The separation of Australia from Antarctica was very strong, and the Iberian and Cantabrian Mountains rose.
- Disappearance of archaic mammals from the early Cenozoic times.
- Extinction of the Creodonts.
- The first true carnivores emerged.
- The first anthropoid primate, which disappeared at the end of the age.
- Oreodonts, herbivores of small size.
- Elephants
- Apes
- Evolution of rhinos.
- Evolution of horses.
- Miocene . It is the one that concluded with the formation of the mountain ranges of the Alps and the Himalayas. The Strait of Gibraltar does not yet exist, and the southern part of the Iberian Peninsula sees the formation of raised reliefs . The union of North America with South America begins, and sedimentary erosion forms deposits and marine basins, later converted into oil reserves. The level of the Mediterranean Sea drops, until it almost becomes a great desert , which causes the communication with the Atlantic Ocean to be lost. The following species developed in this subperiod.
- Apes
- Orangutans
- Marsupials in Europe and North America
- Cats
- Megatherium, a giant placental sloth.
- Amphicyon, the well-known bear-dogs.
- Hominids (Sahelanthropus, Ardipithecus, Proconsul africanus)
- Pliocene . Where the continents and oceans began to shape the current shape they have. The Panama Canal was produced, and the Alps continued to rise. The Strait of Gibraltar opens, filling the trench that was formed by the collapse of the axis of the Atlas-Betic chain, and the Mediterranean Sea rose a few meters. The temperature dropped a lot, reaching the formation of coniferous forests and tundras. Some species developed:
- Mastodon, equivalent to the mammoth but with a large number of teeth.
- Elephants
- Hippos
- Lions
- Armadillo
- Lazy
- Foxes
- Cougars
- Lynxes
- Different species of hominids (Paranthropus, Australopithecus, Homo habilis, Homo erectus)
