Mesozoic Earth ] Back | Next >

 North America
 68 million years ago

Mean atmospheric O2
 150% of modern level

Mean atmospheric CO2
 6x pre-industrial level

Mean temperature
 4C above modern level

Mesozoic Earth - A 2,000 pound tyrannosaur foraging for its next meal while a rat-sized Purgatorius hides amongst the undergrowth of a cretaceous forest; dinosaurs; mammals; protoprimates - Natural History Illustration Geologic Time Scale

 Era: Mesozoic
  Period: Cretaceous
   Epoch: Late
    Age: Maastrichtian


Purgatorius and Bistahieversor

A rat-sized proto-primate of the genus Purgatorius hides amongst the undergrowth of a cretaceous forest while a 30-foot-long, 2,000 pound tyrannosauroid dinosaur of the genus Bistahieversor forages for its next meal in what is today the western United States.

is the genus for several species of small omnivorous mammals that are believed to be the among the earliest ancestors of modern-day chimps, rhesus monkeys, and humans. The extinction of the larger and more powerful dinosaurs may have been what led to world's domination by mammals today.

While there is no direct evidence that Purgatorius and Bistahieversor ever shared the same wilderness, this image is yet illustrative of the predator-prey relationship that characterized dinosaurs and mammals for many millions of years.




Copyright Walter B. Myers. All rights reserved.

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