The truth behind hundreds of mysterious spheres stranded on British beaches

Beachgoers in Devon and Cornwall, England, were left baffled when they found hundreds of strange spheres stranded on the sand.

The ball that looks like a rugby ball is actually the carcass of a sea urchin. Photo: APEX.

According to The Sun, the rugby ball-shaped spheres have been found in piles along the Devon and Cornwall coasts. Many parents are keeping their children away from the spheres for fear they are poisonous.

However, oceanography experts say the mysterious sphere is actually the corpse of a species of urchin called the "sea potato" (Echinocardium cordatum), which often buries itself deep in the sand and mud along the British coast.

The "sea potato" urchin lives far out at sea. Photo: Wikipedia.

The mass death of hundreds of sea urchins that washed ashore on August 17 may be the largest mass death of the species ever recorded. It occurred after a long period of calm seas that allowed plankton to flourish, forming thick mats on the ocean floor and suffocating the urchins.

According to the Wildlife Trust, sea urchins have small yellow-brown spines, but when they die, only their brown shells wash ashore. The last mass death of sea urchins was in May 1995 off the southern coast of England.

According to VNE