32 - 90 MyF
Earth 5 million years from now
Mean atmospheric Oxygen level

ca. 20 Vol %

105% of modern level

Mean atmospheric Carbon Dioxide level

ca. 750 ppm

3 times pre-industrial level

Mean surface temperature (°C)

ca. 14 °C

3 °C above modern level

Major events
  • Formation of the African Rift Ocean
  • Formation of Borealia
  • Postocene-Calderan Extinction
  • Decline of Mammalian Diversity
  • Rise of Reptilian Diversity

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Future of The World
This is a part of Future of The World: a collaborative project about our planet's future
Earth 5 million years from now

The Basilozoic is the era that follows the Cenozoic era, spanning from thirty two to ninety million years in the future.The Basilozoic got its name from the word "basil", meaning life; and "zoic", meaning animal; its name in English means king life, referring to the spectacular fauna of the era. At the beginning of the era there is an extinction that wipes out most large mammals, allowing other creatures to become dominant.

The beginning of the Basilozoic is marked by the end of the Postocene, the last epoch of the Cenozoic which lasts from eight million years to thirty-two million years, and the Postocene-Calderan extinction. Due to extensive volcanism, plate tectonics, and the release of greenhouse gases, an event occurs that leads to the extinction of all mammalian megafauna, half of bird species, and a plethora of other vertebrates, making the P-Go event the worst extinction since the K-Pg extinction.

The first period of the Basilozoic is the Calderan; this period lasts from thirty-two million to fifty million years in the future. From the Calderan onwards, there are three proper continents; South America, Antarctica, and the supercontinent of Borealia (which consists of Eurasia, Africa, North America and Australia). For the first half of the Calderan, the Earth is still recovering from the recent P-Ca extinction, which allows reptiles to become more dominant. The African Rift ocean finally forms into a true ocean basin around this time. Near the start of the Claderan, a minor thermal maximum occurred, leading to the extinction of the remaining large mammals that survived the P-Ca extinction.

The second period is the Adamantemian, which lasts from fifty million to seventy-five million years from now. This period is well into the dominion of reptiles, and this isn't more apparent than on the Borealian supercontinent; mammals are restricted to similar niches held during the Mesozoic, while reptiles have filled the niches left by the extinct mammal megafauna. Antarctica and South America, however, have not had the same explosion of reptilian diversity; mammals are still the dominant animals on these two continents, and recovered fairly quickly compared to Borealian mammals (likely due to their isolation).

The third period of the Basilozoic is the Megistian, which lasts from seventy-five million years to ninety million years. The Earth has finally begun to cool down, with temperatures getting closer to those during the Cenozoic. This in turn leads to the growth of the polar ice caps and the reduction of the once widespread forests and marshes, although they still remain quite abundant. In Borealia, reptiles are still the dominant animals, being versatile enough to adapt to the cooling climate. However, flying reptiles have begun to decline, and by the end of the Megistocene, they have been pushed to extinction by the more adaptable birds.