Newly found 550mn year old organism thought to be ‘first with skeleton’

Washington -  The oldest animal with a skeleton has reportedly been discovered in Australia by a team of paleontologists.

The organism, called Coronacollina acula, is between 560 million and 550 million years old, which places it in the Ediacaran period, before the explosion of life and diversification of  organisms took place on Earth in the Cambrian.

The finding provides insight into the evolution of life – particularly, early life – on the planet, why animals go extinct, and how organisms respond to environmental changes. The discovery  also can help scientists recognize life elsewhere in the universe.

The Ediacaran Period, named after the Ediacara Hills of South Australia, ranges 630-542 million years ago. The Cambrian Period, marked by a rapid diversification of life-forms on Earth as  well as the rise of mineralized organisms, ranges 542-488 million years ago.

“Up until the Cambrian, it was understood that animals were soft bodied and had no hard parts,” said Mary Droser, a professor of geology at the University of California, Riverside, whose  research team made the discovery in South Australia.

“But we now have an organism with individual skeletal body parts that appears before the Cambrian. It is therefore the oldest animal with hard parts, and it has a number of them - they would  have been structural supports - essentially holding it up. This is a major innovation for animals,” she said.

Droser says that it provides a link between the two time intervals.

She said that it is “tremendously exciting because it is the first appearance of one of the major novelties of animal evolution.”

The appearance of Coronacollina acula signals that the initiation of skeletons was not as sudden in the Cambrian as was thought, and that Ediacaran animals like it are part of the  evolutionary lineage of animals as we know them.

“The fate of the earliest Ediacaran animals has been a subject of debate, with many suggesting that they all went extinct just before the Cambrian… Our discovery shows that they did not,”  she said.

Study results appeared online on February 14 in Geology.