Mean atmospheric O2
Geologic Time Scale
Pterosaurs amidst Bjuvia
A pterosaur alights near the bank of a shallow pond, attracted by the prospect of a dinner of carrion 228 million years ago.
Earth's open and sunny plains were once home to cycads of the genus Bjuvia. Bjuvia, a cone-bearing seed plant, resembled modern palms, however they were more closely related to pines. Adult Bjuvia grew to a height of 25 feet and became extinct about 210 million years ago during the Late Triassic period.
Also during this time the skies were home to a flying variety of reptiles known as pterosaurs. While pterosaurs' reptilian origins appear clear, they were not related to birds, and it isn't certain whether they were even related to dinosaurs. There were many varieties of pterosaur during their reign of 160 million years, becoming extinct, along with most of the dinosaurs, about 65 million years ago.
Copyright © Walter B. Myers. All rights reserved.
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