Earliest Ancestor of Many Modern Animals May Have Been Found in Australia

The earliest known ancestor of most familiar forms of animal life living on the planet today appears to have been identified in outback Australia, revealing a strange, worm-like organism that deserves our respect and gratitude.

Ikaria wariootia, a sluggish blob about the size of a grain of rice, might not look like much, but scientists think it could be the oldest example ever discovered of bilaterians: animals with bilaterally symmetrical bodies (mirrored left and right sides) and a front side and back side, usually sporting a mouth and an anus. Like you, in other words.

"This is what evolutionary biologists predicted," says geologist Mary Droser from UC Riverside. "It's really exciting that what we have found lines up so neatly with their prediction."

In recent years, scientists have learned a lot about the spongy, slimy multicellular organisms that make up what's known as the Ediacaran biota – a mysterious group of ancient life-forms who existed before the Cambrian explosion.

One of these creatures in particular, called Dickinsonia, has drawn a lot of attention among researchers, being identified a couple of years ago as the world's earliest known animal in the fossil record.

Not everything that emerged in this period is directly related to humans, though, nor to all the other animals with bilateral physiology. Read the full article.