Image credit: Ned M. Seidler, National Geographic
Ker Than for National Geographic News; August 8, 2011 -
Predatory dragonflies the size of modern seagulls ruled the air 300 million years ago, and it’s long been a mystery how these and other bugs grew so huge.
The leading theory is that ancient bugs got big because they benefited from a surplus of oxygen in Earth’s atmosphere. But a new study suggests it’s possible to get too much of a good thing: Young insects had to grow larger to avoid oxygen poisoning.
Banded Sea Krait
Photograph by David Fleetham/Visuals Unlimited, Inc./Getty Images
“The banded sea krait’s lethal venom packs a punch ten times more toxic than a rattlesnake’s, but fortunately these serpents are so meek that human bites are rare. Kraits cruise the shallow, tropical waters of coral reefs and mangrove swamps. But, alone among the sea snakes, they are amphibious and able to spend up to ten days at a time on land. Sea kraits hit the beach to digest their food (mostly eels and fish), mate, and lay eggs.”
Click the photo to see more from National Geographic’s gallery of toxic and stinging sea creatures.