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 North America
 280 million years ago

Mean atmospheric O2
 115% of modern level

Mean atmospheric CO2
 3x pre-industrial level

Mean temperature
 2C above modern level


Paleozoic Earth - A Dimetrodon in a Permian forest of Alethopteris (Medullosales) with a centipede, spider, dragonfly, slug and lizard - Natural History Illustration Geologic Time Scale

 Era: Paleozoic
  Period: Permian
   Epoch: Cisuralian
    Age: Artinskian


Dimetrodon amidst Alethopteris

A synapsid from the genus Dimetrodon was the apex predator of its time and likely had few enemies save for other Dimetrodon. They came as large as 11 feet long, 4 feet tall, and weighing as much as 300 pounds. Their reptilian hide, a relative novelty for that period, ensured their survival out of water. The large sail may have helped them to regulate body temperature, a survival advantage during the extremes of hot and cold during the Early Permian.

Given that Dimetrodon is more closely related to mammals than dinosaurs, it could be that our own body's ability to regulate temperature had its origin in this ancient beast.

Alethopteris is the genus of a seed fern that populated much of the world during the Carboniferous and Early Permian periods. Long extinct, fossilized leaves from the Alethopteris are commonly found today.



Copyright Walter B. Myers. All rights reserved.

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