Treasure trove of marine fossils from 'Cambrian explosion' found in China

**Treasure trove of marine fossils from 'Cambrian explosion' found in China
Digging up a Qingjiang Fossil on a bank of the Danshui River, near its junction with the Qingjiang River, Hubei Province, China. Credit: Dong King Fu

A team of researchers from Northwest University and Guizhou University, both in China and one from the U.S., has found and partially excavated a new treasure trove of marine fossils from the "Cambrian explosion" in southern China. In their paper published in the journal Science, the group describes what has been found thus far. Allison Daley, with the University of Lausanne, has published a Perspective piece on the work by the team in China in the same journal issue.

The Cambrian period was a time during which most of the early ancestors of all animals came to exist—scientists believe it occurred from approximately 560 million years ago to approximately 540 million years ago. The emergence of such a wide variety of phyla in such a short time has led to use of the term "Cambrian explosion" to describe it. Research on the period began in earnest back in 1909, when scientists discovered a site known as the Burgess Shale was discovered—they found fossils there that were so well preserved that such things as eyes and internal body were visible. Since that time, other sites have been found, as well—all in shale beds. In this new effort, the researchers report on the discovery of a new site close to the Danshui River, which the researchers refer to as the Qingjiang biota—and initial reports suggest it could provide the best collection of Cambrian fossils to date.

The researchers have been hard at work unearthing fossils for four years already, and have found dozens of species, half of which have never been seen before. But the best news is that the fossils are better preserved than at other sites—the researchers have clear examples of soft-bodied creatures, for example, and detailed soft body parts.

The researchers note that a lot of things had to go right for the fossils to be so well preserved. It would have been very deep underwater approximately 550 million years ago—at such depths, there was very little oxygen to sustain organisms that would have decomposed the bodies of animals that fell to the bottom of the sea. Those bodies were covered by millions of years of sediment before conditions changed and the area was pushed up to become land. And over the course of all those years, the area would have been very stable—no volcanoes or earthquakes disrupting the ground.

**Treasure trove of marine fossils from 'Cambrian explosion' found in China
Digging up a Qingjiang Fossil on a bank of the Danshui River, near its junction with the Qingjiang River, Hubei Province, China. Credit: Dong King Fu

Explore further

Scientists take a closer look at Earth's first animals

More information: Dongjing Fu et al. The Qingjiang biota—A Burgess Shale–type fossil Lagerstätte from the early Cambrian of South China, Science (2019). DOI: 10.1126/science.aau8800

Allison C. Daley. A treasure trove of Cambrian fossils, Science (2019). DOI: 10.1126/science.aaw8644

Journal information: Science

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Citation: Treasure trove of marine fossils from 'Cambrian explosion' found in China (2019, March 22) retrieved 15 September 2019 from https://phys.org/news/2019-03-treasure-trove-marine-fossils-cambrian.html
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Mar 23, 2019
I have a hard time imagining "soft-bodied creatures ... and detailed soft body parts" surviving 540 million years under any conditions. Perhaps they are mistaken (drastically) about the age of these fossils.

Mar 23, 2019
I have a hard time imagining "soft-bodied creatures ... and detailed soft body parts" surviving 540 million years under any conditions. Perhaps they are mistaken (drastically) about the age of these fossils.

They're not soft, NOW...
They are the fossilized remains of soft bodied creatures....

Mar 24, 2019
oh--So that's how you use a pickaxe.

Mar 24, 2019
rubem as with petrified wood, the soft * not so gard parts are mineralized. Think taking an impression of an item you want to oreserve. By carefully cobering with clay. Letting that dry until you can separate, carefully, the original & the impression. Then baking the clay impression till it is a hard solid.

Then comsider, Nature doing that billions of times a day for a billion years. Since we only can expound on what we actually find? It can make for a lot of confusion trying to categorize all the variations. Until a sufficient number of fossils are collected to begin to see a pattern of evolution.

For your amusement & edification...
Wiki Amber
Coprolites
Pompeii & Herculaneum

Mar 25, 2019
This is the Lagerstätte of Lagerstättes. "The researchers note that a lot of things had to go right for the fossils to be so well preserved".

Not only extraordinary preservation among a series of already extraordinary preservations - Ediacaran and Cambrian Lagerstättes are for some still unknown reason unique - but likely extensive and with several ecologies - there are already 50 % unknown species among 20,000+ and counting fossils.

Speaking of which, the latest papers tie the later Ediacaran "Avalon explosion" diversification with the now known animal Dickinsonia with the early Cambrian biota. Meaning - still arguably of course - continuity and a long "tail" towards the modern body plan diversification.

Mar 25, 2019
I have a hard time imagining "soft-bodied creatures ... and detailed soft body parts" surviving 540 million years under any conditions. Perhaps they are mistaken (drastically) about the age of these fossils.

They're not soft, NOW...
They are the fossilized remains of soft bodied creatures....


While we don't know why the early fossil sites are so preserved - perhaps a combination of low oxygen conditions deep down, absence of animals that could rework larger dead animals and absence of plants that prevented mud slides - we do know that some or all of these places were covered in mud or sand from distant underwater avalanches.

The Qingjiang Lagerstätte was deep water, so it is initially thought the animals - that needed lots of oxygen - died further up and slid down as well.

Mar 25, 2019
torbjorn, you left out an important reason that a fossil site survives as "pristine"

& that reason is that the property owner. building contractor. road builder, did not have the opportunity to obliterate the site before it's publicized discovery.

"Fucking professors! There goes our building schedule, right down the toilet!"

& yes, that is a direct quote I heard about thirty years ago.

Mar 26, 2019
torbjorn, you left out an important reason that a fossil site survives as "pristine"

& that reason is that the property owner. building contractor. road builder, did not have the opportunity to obliterate the site before it's publicized discovery.


The map of the putative locale shows a 200 km segment, so that is not a problem here.

Sure, the world is not ideal for anything specific. But in general for this area, builders et cetera are a boon and a problem because they uncover and find many paleontological or archaeological locales that would else be unknown. The trick is to have requisite laws and funds for quick digging where the buildings et cetera will go up (or sometimes be redirected for one among several important reasons such as cultural importance), and anything else like here is just years of digging. (I believe the papers announcing this follows six years after the discovery and after three years or so of field work.)

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