Posted on Friday 13 October 2006
Mongabay.com - USA
The paper, “No giants today: tracheal oxygen supply to the legs limits beetle size,” based on research by a team of American researchers, offers evidence that Paleozoic insects were substantially larger because they had a richer oxygen supply. During the late Paleozoic period, about 300 million years ago, the air’s oxygen content was around 35 percent, compared to 21 percent today. As a result some dragonflies had two-and-a-half-foot wing spans, while giant spiders roamed the ancient forests.
