Remains of oldest human ancestor found in China

Remains of oldest human ancestor found in China An international team of scientists in central China have discovered fossils belonging to the oldest human ancestor found to date. The fossils are said to be 540 million years old yet appear to be “exquisitely well preserved.”

The collaborative research effort was performed by scientists from the University of Cambridge in the UK and Northwest University in China. The results were published in the journal Nature.

The oldest human ancestor is named Saccorhytus due to the sack-like features on its body and giant mouth. The sea creature marks the earliest known step on the evolutionary path that led to both humans and fish.  This category of animals are called “deuterostomes” and are ancestors to a wide array of vertebrates.

Previously discovered deuterostomes were from 510 to 520 million years old, a time when the creatures had already started to diversify.

Saccorhytus measured roughly 1 mm in length and is thought to have consumed and excreted food through the same orifice. Its massive mouth suggests that it ate by engulfing its food. The body was covered in a thin skin and flexible muscles.

“To the naked eye, the fossils we studied look like tiny black grains, but under the microscope the level of detail was jaw-dropping,” Professor Simon Conway Morris from the University of Cambridge told BBC News.

“We think that as an early deuterostome this may represent the primitive beginnings of a very diverse range of species, including ourselves. All deuterostomes had a common ancestor, and we think that is what we are looking at here.”

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By Rory Arnold, Earth.com Staff Writer

Images: S Conway Morris, University of Cambridge

Jian Han, Northwest University