In the previous article, we discussed the first period of the Cenozoic. Now it is time we move on to the period before our current one- The Neogene period. We divide it into two epochs- the Miocene and The Pliocene.
The First Modern Mammals
The first modern mammals show up in the Neogene. ‘Hell pigs’ went extinct at the end of the period. Since the continents separated completely, we should discuss them separately. North America was dominated by rodents, Mammut, bears. In Africa and Eurasia first apes appeared, however, they developed into hominins mostly in Africa, where also a human-chimpanzee divergent appeared. Successful Asian mammals include hyenas, stegodonts, and hyraxes. Rhinos became extinct in Asia, but they survived in Africa. First giraffes and elephants appeared. In the oceans, there were 20 species of baleen whales, compared to today’s six. Seals, which appeared at the end of the Paleogene, became more aquatic. Australia started developing its own unique fauna- kangaroos and wombats developed in the Pliocene.
Reptiles and Birds of the Neogene Period
Despite mammals, other groups also diversified. All of the modern genera of birds developed by the end of the period, starting with owls and cockatoos. Due to the development of grasslands, snakes became more important and started to diversify. Vipers and elapids dominated their niches in North America. In the Pliocene crocodiles and alligators went extinct in Europe, due to climate change. However, in North America modern alligators diverse and survived until today. Crocodilians also did great in Asia and South America. However, in its freshwaters, a giant ancestor of modern piranha dominated. Penguins appeared in New Zealand, along with kiwis and huge turtles.
Development of Modern Ecosystems
Insects and flowering plants coevoluted, so did many other pairs or groups of species. That led to the creation of complex, modern ecological relations between organisms. Another important factor was the plant diversification. Due to the cooling tendencies in climate, the deciduous forests partially replaced the rainforests. That created new ecological opportunities for many animals and led to the development of many species. Grasses continued to spread through climatic zones and continents, creating savannahs, pampas, and steppes. In addition, Cycads diversified, after many years on the border of extinction. That many changes led to big climate fluctuations, intensifying the cooling trend from the previous period.
Beginning of the Current Ice Age
The cooling and drying trend of the Paleogene continued, rising even due to the flora activity. However, the global temperature in the Pliocene was still 2-3 degrees Celcius higher than today. Sea levels were 25m higher, but the CO2 levels were very similar to today’s ratings. Due to the continuing cooling trend, the ice started to spread. That led to the formation of the Arctic by the end of the period. Greenland and Antarctica also started to freeze. That is how our current Ice Age began and in the next period, the ice would continue to spread.
Changes in Earth during the Neogene
The continents of the Neogene seem very similar to it’s today shapes. Every one of them was no further than 250km from today’s position. However, there were still some major changes to happen. Greenland was separating from North America and other islands were still in formation. The North-South America border established, but the Antilles were also forming. In Eurasia, the Mediterranean, Red, and Black seas were forming. The Iberian peninsula was separating from Africa, the Filipinos were separating from Asia. India became an integral part of the continent and Australia drifted away from others. By the end of the Pliocene, Artic formed and Antarctica was covered with ice.
The Neogene Period Evidence
There are many important pieces of evidence from the Neogene period. There are fossils of the Eucalyptus leaves from New Zealand, however today we can only see them in Australia. A recent study suggests that saber-toothed cats were family-oriented creatures, wonderfully adapted to conditions all around the globe. It is still unknown how and why they went extinct. There are also many fossils of hooves of grazing animals, which developed due to the grasslands spreading. Among many species of enormous sharks, hunting the whales, we can find megalodons or livyatan. There are also skulls of first hominids, enabling us to deeply analyze the evolution of humankind.
I hope that the article helped you learn about the recent development of life. If you enjoyed it, please share it with family and friends. In the next one we will be moving on to our last and current period- The Quaternary. Until then, feel free to ask questions using the contact form or just writing me an email.