Bag-like sea creature was humans' oldest known ancestor: A tiny sea creature identified from fossils found in China may be the earliest known step on an evolutionary path that eventually led to the emergence of humans

Bag-like sea creature was humans' oldest known ancestor: A tiny sea creature identified from fossils found in China may be the earliest known step on an evolutionary path that eventually led to the emergence of humans: Researchers have identified traces of what they believe is the earliest known prehistoric ancestor of humans -- a microscopic, bag-like sea creature, which lived about 540 million years ago.

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