Scientists have identified the earliest known example animals that lived 518 million years ago, evolving to lose body parts that were no longer needed. The mystery surrounded by the evolution of Facivermis, a worm-like creature has always puzzled the researchers. Facivermis yunnanicus was a worm-like creature from the Cambrian period, when the first complex animals evolved in the seas. The ancient worm was 10 centimetres long and had five pairs of sharp legs on its front half, while its rear end was swollen. But the new study has revealed that Facivermis was itself a lobopodian that lived a tube-dwelling lifestyle, and evolved to lose its lower limbs. Researchers believe such studies will help them to understand the hierarchy of evolution and figure out where the adaptations and body parts we now see have come from.
