Newly Described Fossil is Half a Billion Years Old

A 520 million year old fossil of a primitive relative of star fish and sea urchins has been described as a new species in the latest edition of the journal Proceedings of the Royal Society B.

The newfound creature, called Helicocystis moroccoensis, belongs to the phylum of marine animals known as echinoderms. According to the abstract of the paper on the Helicocystis moroccoensis, the echinoderms are unique in the animal kingdom because of their pentaradial body plan, and this ancient specimen provides the oldest known example of one. The find will help scientists complete the fossil record of ancient marine life.

"By filling an important gap, this fossil reveals the common pattern that underpins the body plans of the two major echinoderm clades," the researchers wrote in the abstract.

While it's shaped more like a cigar than a starfish, the Helicocystis moroccoensis'  spiral plating gives researchers a clue to how the more visually robust echinoderms evolved.

Paleontologist Andrew Smith made the discovery with his colleagues in 2012 when they were excavating in sediments in the Anti-Atlas Mountains in Morocco. While the animal's skeleton was long since disintegrated, it left a distinct impression in the sediments.

The creature was named after Morocco, the country where it was found, according to a LiveScience report, though when it was alive Earth was dominated by the supercontinent Gondwana during a period called the Cambrian Explosion.

H. moroccoensis was a diminutive creature, only about 1.6 inches (4 cm) long, and it fed from a mouth at the top of its cylindrical body.

"It's a cigar-shaped beast, and it was able to expand and contract that cigar shape," Smith said to LiveScience. "Sometimes it could be short and fat, and sometimes it could be long and thin."

View a slideshow of photos of the ancient creature here.