蜜芽传媒

Scientists have identified the earliest known animal in the geological record. It's a 558-million-year-old oval-shaped creature that may have borne a superficial resemblance to a segmented jellyfish.

But as Professor Jochen Brocks from the research school of earth sciences at the Australian National University explains, they have been extremely difficult to classify, and their position on the tree of life has been one of the greatest mysteries in palaeontology.

(Photo shows: A organically preserved Dickinsonia fossil that was discovered near the White Sea area in northwest Russia. Credit: EPA/Australian National University/ Ilya Bobrovskiy)