The recently discovered fossil, named Shishania aculeata, shows that the earliest molluscs—animals without backbones—were flat, shell-free slugs with spiky armor to protect them.
According to experts in a recent study, the animal’s underbelly consisted of a slug-like muscular foot that it would have used to travel across the seafloor.
The species, which originated around 514 million years ago during the early Cambrian period of geological time, was discovered in well-preserved fossils from the eastern Yunnan Province in southern China.
Shishania was unique among mollusks in that it lacked a shell covering its body.
It stands for a very early phase of the animal’s evolution.
It is believed that the animal’s cones on top helped in mobility and defense.
Mollusks today exist in a wide variety of shapes and sizes, from clams and snails to highly sophisticated species like octopuses and squids.
