David Bressan
FORBES
Senior Contributor
I deal with the rocky road to our modern understanding of earth
Jan 21, 2024
Tribrachidium heraldicum, one of the most enigmatic critters from the Ediacaran fauna.
Senior Contributor
I deal with the rocky road to our modern understanding of earth
Jan 21, 2024
Tribrachidium heraldicum, one of the most enigmatic critters from the Ediacaran fauna.
D.BRESSAN
A new study has for the first time precisely dated some of the oldest fossils in the world, helping to track a pivotal moment in the history of Earth when the first multicellular life appeared.
In 1947, geologist Reginald C. Sprigg announced the discovery of fossils of possible animal-like creatures from the Ediacara Hills in Australia. Preliminary dating of the rock formations revealed that the Ediacara Fauna was living more than 500 million years ago in a shallow sea.
These fossils occur so early in the evolutionary history of animals that in many cases they appear to be experimenting with different ways to build large multicellular bodies. They include many weird organisms of unknown affinity, like Dickinsonia, a sort of hybrid between a worm and a jellyfish, Charnia, a segmented and branched organism, or Tribrachidium, showing a threefold rotational symmetry not found in any modern animal.
Using volcanic ash layers like bookmarks, a new study pinpointed exactly one of the earliest occurrences of Ediacara-like fossils in the geologic record.
“Located in the Coed Cochion Quarry in Wales, which contains the richest occurrence of shallow marine life in Britain, we used outfall from an ancient volcano that blanketed the animals as a time marker to accurately date the fossils to 565 million years, accurate down to 0.1 per cent,” so lead author PhD student Anthony Clarke, from the Timescales of Mineral Systems Group within Curtin’s School of Earth and Planetary Sciences U.K.
This discovery also helps correlate the Welsh site with similar fossil sites worldwide. Ediacaran fossils are known from over 40 sites located in South Australia, Ukraine, Newfoundland, Namibia and around the White Sea. Most Ediacaran strata date from about 580 to 539 million years in age.
Based on the age and the preserved species, the Welsh fossils appear directly comparable to the famous fossils of Ediacara in South Australia, eastern Newfoundland and the White Sea area, explains study co-author Professor Chris Kirkland.
The temporal and faunal similarities suggest that the Ediacaran organisms were quite more successful in evolutionary terms than previously believed. They were part of an ancient living community with global distribution, colonizing shallow- to deep-sea environments existing at the time around the first continents.
Ruling the seas for roughly 96 million years, the Ediacara fauna went extinct about 539 to 500 million years ago in the first known mass extinction, marking the end of the Proterozoic and the beginning of the Phanerozoic—the time in Earth's history ruled by modern animals.
The full research paper,"U–Pb zircon-rutile dating of the Llangynog Inlier, Wales: constraints on an Ediacaran shallow 1 marine fossil assemblage from East Avalonia" was published in the Journal of the Geological Society and can be found online here. Additional material and interviews provided by The Geological Society.
A new study has for the first time precisely dated some of the oldest fossils in the world, helping to track a pivotal moment in the history of Earth when the first multicellular life appeared.
In 1947, geologist Reginald C. Sprigg announced the discovery of fossils of possible animal-like creatures from the Ediacara Hills in Australia. Preliminary dating of the rock formations revealed that the Ediacara Fauna was living more than 500 million years ago in a shallow sea.
These fossils occur so early in the evolutionary history of animals that in many cases they appear to be experimenting with different ways to build large multicellular bodies. They include many weird organisms of unknown affinity, like Dickinsonia, a sort of hybrid between a worm and a jellyfish, Charnia, a segmented and branched organism, or Tribrachidium, showing a threefold rotational symmetry not found in any modern animal.
Using volcanic ash layers like bookmarks, a new study pinpointed exactly one of the earliest occurrences of Ediacara-like fossils in the geologic record.
“Located in the Coed Cochion Quarry in Wales, which contains the richest occurrence of shallow marine life in Britain, we used outfall from an ancient volcano that blanketed the animals as a time marker to accurately date the fossils to 565 million years, accurate down to 0.1 per cent,” so lead author PhD student Anthony Clarke, from the Timescales of Mineral Systems Group within Curtin’s School of Earth and Planetary Sciences U.K.
This discovery also helps correlate the Welsh site with similar fossil sites worldwide. Ediacaran fossils are known from over 40 sites located in South Australia, Ukraine, Newfoundland, Namibia and around the White Sea. Most Ediacaran strata date from about 580 to 539 million years in age.
Based on the age and the preserved species, the Welsh fossils appear directly comparable to the famous fossils of Ediacara in South Australia, eastern Newfoundland and the White Sea area, explains study co-author Professor Chris Kirkland.
The temporal and faunal similarities suggest that the Ediacaran organisms were quite more successful in evolutionary terms than previously believed. They were part of an ancient living community with global distribution, colonizing shallow- to deep-sea environments existing at the time around the first continents.
Ruling the seas for roughly 96 million years, the Ediacara fauna went extinct about 539 to 500 million years ago in the first known mass extinction, marking the end of the Proterozoic and the beginning of the Phanerozoic—the time in Earth's history ruled by modern animals.
The full research paper,"U–Pb zircon-rutile dating of the Llangynog Inlier, Wales: constraints on an Ediacaran shallow 1 marine fossil assemblage from East Avalonia" was published in the Journal of the Geological Society and can be found online here. Additional material and interviews provided by The Geological Society.
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