Latest Issue of Science News


News

Oxygen blew up ancient amoebas

Single-celled creatures' size spiked as oxygen levels rose

MINNEAPOLIS — Giant armor-clad amoebas that once swam Paleozoic seas may have owed their monstrous size to something in the water: oxygen. 

A new look at the fossil record suggests that a spike in oxygen levels supersized many species of these fusulinids, a now-extinct type of single-celled microbe called foraminifera. About 300 million years ago, when the atmosphere contained almost enough oxygen to spontaneously combust, some of these critters grew to be 10 centimeters long. They would have been visible to the naked eye.

Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.

X
This article is available only to subscribing members. Join SSP today or Log in.