May 17, 2016, BY JOSHUA NEVETT, MARK WAGHORN, Morror 

These ancient marine fossils are among the earliest known complex life forms ever discovered on Earth.

At more than 1.5 billion years old, the primitive organisms predate predate previously recorded fossils of a similar size by more than 600 million years.

Measuring up to a foot in length, the fossils, found in China, are believed to be specialised cells encased in membranes named eukaryotes.

Most living things today are made up of these cells, including animals, plants and humans.

But while the first eukaryotes are thought to have appeared more than 400 million years earlier, these fossils allow experts to accurately time stamp the moment single cell organisms became more complex.

The finding, reported in the journal Nature Communications, may represent new evidence for the early evolution of eukaryotic organisms large enough to be visible without a microscope.

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The astonishing discovery was made by Professor Maoyan Zhu and a team of archaeologists who found 167 specimens 70 miles from Bejing in North China.

Zhu, along with his colleagues, identified four distinct shapes among 53 of the total.

Nearly half are linear while the others are wedge, oblong or tongue shaped.

They are preserved as carbon rich compressions and are up to a foot long and eight centimetres wide.

The authors also found fragments of tiny, closely packed cells, which they interpreted as further evidence for multicellularity in these fossils.

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Prof Zhu, of the Chinese Academy of Sciences, Beijing, described them as "multicellular eukaryotes of unprecedentedly large size."

He said: "Fossils of macroscopic eukaryotes are rarely older than the Ediacaran Period (635-541 million years), and their interpretation remains controversial."

"The new fossils provide the strongest evidence yet that multicellular eukaryotes with decimetric dimensions and a regular developmental program populated the marine biosphere at least a billion years before the Cambrian Explosion."

He said life suddenly and rapidly flourished some 550 million years ago.

Prof Zhu said: "We conclude the compressions record a modest diversity of macroscopic multicellular eukaryotic organisms that lived in shelf areas of early Mesoproterozoic oceans."

Although large, the branches known as thalli are thin, which would have facilitated consumption of nutrients and gases.

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Prof Zhu added: "The fossils provide the most compelling evidence yet reported that by the beginning of the Mesoproterozoic Era, 1,600 million years ago, eukaryotic organisms had evolved macroscopic form, multicellularity with limited cell differentiation, and probably photosynthesis.

"Continuing research promises new insights into marine ecosystems in the low oxygen world caricatured misleadingly as a 'boring billion' year interval of evolutionary as well as environmental stability."

Single-celled organisms emerged from the primordial soup about 3.4 billion years ago.

But it was another 1.4 billion years before the first truly multicellular organism, called Grypania spiralis, appears in the fossil record.

Grypania was one of the few known examples of complex life until about 550 million years ago, when the fossil record explodes in diversity.

From: http://www.mirror.co.uk/news/world-news/first-life-earth-discovered-19-7991860#ICID=nsm