Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Greening of the Earth pushed way back in time

23.07.2013
Researchers say a newly named South African fossil points to rising oxygen and life 2.2 billion years ago

Conventional scientific wisdom has it that plants and other creatures have only lived on land for about 500 million years, and that landscapes of the early Earth were as barren as Mars.


This is an interpretive view of Diskagma buttonii with exterior view, left, and cross section. The fossils are the size of match heads and were found connected into bunches by threads in the surface of an ancient soil from South Africa.

Credit: Courtesy of Gregory Retallack

A new study, led by geologist Gregory J. Retallack of the University of Oregon, now has presented evidence for life on land that is four times as old -- at 2.2 billion years ago and almost half way back to the inception of the planet.

That evidence, which is detailed in the September issue of the journal Precambrian Research, involves fossils the size of match heads and connected into bunches by threads in the surface of an ancient soil from South Africa. They have been named Diskagma buttonii, meaning "disc-shaped fragments of Andy Button," but it is unsure what the fossils were, the authors say.

"They certainly were not plants or animals, but something rather more simple," said Retallack, professor of geological sciences and co-director of paleontological collections at the UO's Museum of Natural and Cultural History. The fossils, he added, most resemble modern soil organisms called Geosiphon, a fungus with a central cavity filled with symbiotic cyanobacteria.

"There is independent evidence for cyanobacteria, but not fungi, of the same geological age, and these new fossils set a new and earlier benchmark for the greening of the land," he said. "This gains added significance because fossil soils hosting the fossils have long been taken as evidence for a marked rise in the amount of oxygen in the atmosphere at about 2.4 billion to 2.2 billion years ago, widely called the Great Oxidation Event."

By modern standards, in which Earth's air is now 21 percent oxygen, this early rise was modest, to about 5 percent oxygen, but it represented a rise from vanishingly low oxygen levels earlier in geological time.

Demonstrating that Diskagma are fossils, Retallack said, was a technical triumph because they were too big to be completely seen in a standard microscopic slide and within rock that was too dark to see through in slabs. The samples were imaged using powerful X-rays of a cyclotron, a particle accelerator, at the Lawrence Berkeley National Laboratory in California.

The images enabled a three-dimensional restoration of the fossils' form: odd little hollow urn-shaped structures with a terminal cup and basal attachment tube. "At last we have an idea of what life on land looked like in the Precambrian," Retallack said. "Perhaps with this search image in mind, we can find more and different kinds of fossils in ancient soils."

In their conclusion, the researchers noted that their newly named fossil Diskagma is comparable in morphology and size to Thucomyces lichenoides, a fossil dating to 2.8 billion years ago and also found in South Africa, but its composition, including interior structure and trace elements, is significantly different.

Diskagma also holds some similarities to three living organisms, which were illustrated microscopically in the study: the slime mold Leocarpus fragilis as found in Oregon's Three Sisters Wilderness; the lichen Cladonia ecmocyna gathered near Fishtrap Lake in Montana; and the fungus Geosiphon pyriformis from near Darmstadt, Germany.

The new fossil, the authors concluded, is a promising candidate for the oldest known eukaryote --an organism with cells that contain complex structures, including a nucleus, within membranes.

"Researchers at the UO are collaborating with scientists from around the world to create new knowledge with far-reaching applications," said Kimberly Andrews Espy, UO vice president for research and innovation, and dean of the graduate school. "This research by Dr. Retallack and his team opens new doors of inquiry about the origins of ancient life on Earth."

The three co-authors with Retallack on the study were: Evelyn S. Krull of the Land and Water Division of the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia's national science agency; Glenn D. Thackray, professor of geology at Idaho State University; and Dula Parkinson of the Lawrence Berkeley National Laboratory.

About the University of Oregon

The University of Oregon is among the 108 institutions chosen from 4,633 U.S. universities for top-tier designation of "Very High Research Activity" in the 2010 Carnegie Classification of Institutions of Higher Education. The UO also is one of two Pacific Northwest members of the Association of American Universities.

SOURCE: Gregory J. Retallack, professor of geological sciences, 541-346-4558, gregr@uoregon.edu

Links:

Retallack faculty page: http://pages.uoregon.edu/dogsci/doku.php?id=directory/faculty/greg/about

Department of Geological Sciences: http://pages.uoregon.edu/dogsci/doku.php

Museum of Natural and Cultural History: http://natural-history.uoregon.edu/

Follow UO Science on Facebook: http://www.facebook.com/UniversityOfOregonScience

UO Science on Twitter: http://twitter.com/UO_Research

More UO Science/Research News: http://uoresearch.uoregon.edu

Note: The University of Oregon is equipped with an on-campus television studio with a point-of-origin Vyvx connection, which provides broadcast-quality video to networks worldwide via fiber optic network. In addition, there is video access to satellite uplink, and audio access to an ISDN codec for broadcast-quality radio interviews.

Jim Barlow | EurekAlert!
Further information:
http://www.uoregon.edu

More articles from Earth Sciences:

nachricht Predicting eruptions using satellites and math
28.06.2017 | Frontiers

nachricht NASA sees quick development of Hurricane Dora
27.06.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>