Chinese researchers uncovered microfossils, which they believe could be mankind's ancestor, various news sites reported citing Journal Nature's study published on Monday.
Saccorhytus, the tiny fossil's scientific name, is a sea creature resembling a bag and believed to have thrived some 540 million years ago.
Its scientific name has relevance to its shape, size and appearance: wrinkled and about a millimeter long. It is also said to have lived in the seabed's sand.
Although discovered on some dry land, half a billion years ago, researchers said the shallow sea would have been the sea creature's location.
According to the study as reported by CNN, Saccorhytus is a member of deuterostomes, which through ages have evolved into diversified branches that include vertebrates like the human species and other sea creatures such as star fish, sea urchins, and squirts as well as acorn worms.
Interestingly, the deuterostomes are several species' common ancestor that has provided for a channel for evolution, which "would lead to humans millions of years later," said the study as reported.
But while saccorhytus may have provided some answers, its discovery was not easy. Researchers also said that because of the diversity that springs from a branch, they found it difficult to have a mental picture of "what the origins would have looked like."
Researchers from England's University of Cambridge and China's Northwest University had to go through 6,000 lbs. of limestone to search for microscopic samples of black flecks on rocks. When scrutinized using a microscope, the fossil's details are seen.
Researchers described the sea creature's body to be elliptical and a bit bilaterally symmetrical, giving it a flexible and flimsy skin.
Its remarkable feature is its big, flexible mouth. It could take in larger prey. Although the researchers said it may lack an anus, its "eight conelike structures around the body appear to be primitive gills" capable of removing excess water.
The significance of the Saccorhytus discovery has to do with the molecular clock, according to the scientists.
"Molecular clocks suggest the origin of the main groups of animals significantly predated what the fossil record would indicate," Simon Conway Morris was quoted as saying. Morris is among the authors of the study and is connected with University of Cambridge's St. John's College.
"One possibility is that the earliest animals were very small and, in normal circumstances of fossilization, very unlikely to survive," Morris said, adding that Saccorhytus might give us a glimpse of a long and cryptic history.