Agnostus pisiformis

Check Out 5 Strange Creatures That Lived on Earth 500 Million Years Ago

Scientists discovered more than 100 Cambroraster fossils in Canada’s Burgess Shale, a fossil site that is over 500 million years old.


Various creatures walked planet earth back in the olden days; some of those creatures are now extinct and can only be observed through fossils.

Following are five bizarre yet fascinating creatures that lived approximately 500 million years ago:

Cambroraster falcatus
Reconstruction of Cambroraster falcatus. Source: Lars Fields

Cambroraster Falcatus:

Scientists and explorers have discovered fossils of Cambroraster falcatus; an ancient predator that lived during the Paleozoic era. Cambroraster was a relative of modern-day insects and was over 30 centimetres long. Scientists discovered more than 100 Cambroraster fossils in Canada’s Burgess Shale, a fossil site that is over 500 million years old. The site has an extensive range of fossiled creatures from the Cambrian period.

Agnostus pisiformis
Sculpture of a pea-sized Cambrian sea creature, Agnostus pisiformis. Source: Esben Horn

Agnostus Pisiformis:

This clam-like creature is known as Agnostus pisiformis, and it lived underwater approximately 500 million years ago. The said creature is just four-tenths of an inch. Scientists and explorers found them perfectly preserved in shale and limestones. According to experts, pisiformis started life as a larva and gradually developed into a shell-like-creature by frequently shedding and regrowing its exoskeleton. Its body was protected by two shields that resembled clamshells.

Reconstruction of Opabinia. Source:


Cambrian seas sheltered multiple bizarre and deadly creatures back in the olden days. Some of the critters living in these ancient seas included Opabinia, which had five eyes and an elephant trunk-like attachment. Opabinia prospered from 505 million years ago to 487 million years ago during the Paleozoic era. It was approximately 2-3 inches in length and is presumed to have been a carnivore.

Reconstruction of Yawunik. Source: Wikimedia Commons


Yawunik is a billion-year-old ancestor of today’s bugs and spiders. However, it did not resemble them in any way or form. It had a head-mounted set of sensory tentacles that doubled as claw-like tools for grabbing and slicing its prey. Yawunik was approximately fifteen-centimetre long. However, it is known for its long tentacles; each appendage ended with the growth of three different claws.‭ ‬Moreover, from the ends of these claws,‭ ‬long wisp-like antennae grew.

Helcocystis moroccoensis
Reconstruction of Helcocystis Moroccoensis. Source:

Helcocystis moroccoensis:

A cigar-shaped creature called Helcocystis moroccoensis has been discovered in Morocco. The fossil of the said creature is approximately 520 million years old. According to various experts, Helcocystis lived during the Cambrian age. It is believed that the said creature could change its body shape from thin to stumpy. Researchers say that it was a transitional animal; it was initially discovered in another form in California.

Most of the earth submerged during the Cambrian age. Multiple species evolved; animals had no choice but to become predators as new species came forth every single day. Researchers have yet to unearth various fossils that are buried in different parts of the world. 

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