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Reported on Oct, 15, 2018, multicellular animal life in the form of a sponge has been dated to at least 100 million years before the Cambrian period, as far back as 660-635 million years ago during the Neoproterozoic Era.
Researchers at the University of California, Riverside, have found the oldest clue yet of animal life, dating back at least 100 million years before the famous Cambrian explosion of animal fossils.
The study, led by Gordon Love, a professor in UCR's Department of Earth Sciences, was published today in Nature Ecology & Evolution. The first author is Alex Zumberge, a doctoral student working in Love's research group.
Rather than searching for conventional body fossils, the researchers have been tracking molecular signs of animal life, called biomarkers, as far back as 660-635 million years ago during the Neoproterozoic Era. In ancient rocks and oils from Oman, Siberia, and India, they found a steroid compound produced only by sponges, which are among the earliest forms of animal life.
So the question for me is -- will we need to assign different dates to the Cambrian?
Why would there be a need to do this?
The "Cambrian Explosion" refers to the sudden appearance in the fossil record of complex animals with mineralized skeletal remains. It may represent the most important evolutionary event in the history of life on Earth.
The OP's link is only describing the discovery of the oldest clue yet of animal life, dating back at least 100 million years before the famous Cambrian explosion of animal fossils.
It has nothing to do with the dates of what occurred during the Cambrian Explosion.
The "Cambrian Explosion" refers to the sudden appearance in the fossil record of complex animals with mineralized skeletal remains. It may represent the most important evolutionary event in the history of life on Earth.
The OP's link is only describing the discovery of the oldest clue yet of animal life, dating back at least 100 million years before the famous Cambrian explosion of animal fossils.
It has nothing to do with the dates of what occurred during the Cambrian Explosion.
It depends on how you define the "Cambrian Explosion"...and just for the record, although I went into education and teaching earth science, my degrees were in geology with an emphasis on invertebrate paleontology of the Paleozoic as exemplified by the fossils of western NYS.
The Cambrian Explosion is defined by some as you represent it, but that definition of it is debated. Others define it simply as the point in time when "most major animal phyla appeared in the fossil record". If we are going to look for other markers, aside from just fossils, we may have to push back the beginning of the Cambrian.
...and just for the record, although I went into education and teaching earth science, my degrees were in geology with an emphasis on invertebrate paleontology of the Paleozoic as exemplified by the fossils of western NYS.
Cool!
Quote:
Originally Posted by phetaroi
The Cambrian Explosion is defined by some as you represent it, but that definition of it is debated.
What exactly is being debated?
Quote:
Originally Posted by phetaroi
Others define it simply as the point in time when "most major animal phyla appeared in the fossil record".
I really don't see much difference between this: The "Cambrian Explosion" refers to the sudden appearance in the fossil record of complex animals with mineralized skeletal remains, and what you posted above.
I see the Cambrian Explosion is just a period in time where fossil records show a huge diversification of animals on earth.
Quote:
Originally Posted by phetaroi
If we are going to look for other markers, aside from just fossils, we may have to push back the beginning of the Cambrian.
One aspect of the debate has long been whether the appearance of mineralized skeletons should mark the beginning of the Cambrian, or whether the "explosion" is better exemplified by mineralized skeletons simply because those mineralized skeletons were more common in the sedimentary record.
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