Small sea life

Small sea life

Credit: Andrew Smith, Proc. Royal Soc. B

In 2012, researchers unearthed a 520-million year old fossilized creature that is one of the earliest known echinoderms with fivefold symmetry.

Ancient find

Ancient find

Credit: Andrew Smith

The animals skeleton had long since disintegrated, but it left a characteristic impression in the sediments of the Moroccan Anti-Atlas Mountains.

Primitive creature

Primitive creature

Credit: Andrew Smith

The creature, dubbed Helicocystis moroccoensis, had five spiral grooves along its body that it opened and closed to capture food.

Strange symmetry

Strange symmetry

Credit: Andrew Smith

Earlier fossils had spiral arrangement of those grooves, or ambulacra, but not the distinctive five point symmetry found in sea urchins, starfish, and other echinoderms.

One of many

One of many

Credit: Andrew Smith

The new creature may help shed light on when and how echinoderms evolved their unique body plans.

Explosion of life

Explosion of life

Credit: Esben Horn

Helicocystis moroccoensis is just one of many primitive creatures that emerged during the Cambrian explosion, a period when the number of species on the planet exploded. Bizarre shrimplike sea monsters known as anomalocaridids grew up to 6 feet long and filled the Cambrian seas.

Ancient insects

Ancient insects

Credit: Yie Jang (Yunnan University)

Another strange creature, a 500-million year old sea creature known as a fuxhianhuiid, had limbs under its head. Throughout the Cambrian period, life experimented with many wacky body plans.