Dickinsonia
Researchers: Dickinsonia (571–541 mya) could have had mouth and guts
Gunter Bechly: Dickinsonia is NOT likely an animal
Rather, he thinks, it is an unknown type of life form, which belonged to “an alien clade,” not certainly related to later life forms. Readers will recall that fats (sterols) were recently recovered from a 558 million-year-old fossil entity, Dickinsonia, which was previously uncertainly classified but is now classified as an animal as a result. Bechly writes, Although we know many well-preserved specimens of Dickinsonia, its affinities in the supposed tree of life have remained extremely controversial for more than 70 years since its description (Shu et al. 2014, Budd & Jensen 2015). This resulted in its wandering across nearly every kingdom and many phyla of life. In 1992 seven authorities among paleontologists were asked by evolutionary biologist Rudolf Raff Read More ›
Rob Sheldon: How we know the 558 mya animal Dickinsonia remains really contained fats
Recently, some readers asked whether the recent Dickinsonia fossil “fats” find from 558 mya featured cholesterol. Our physics color commentator Rob Sheldon explains further: Cholesterol was not found by these researchers, nor did they make announcements of soft tissue in a fossil. What they did find were the breakdown products of cholesterol called “sterols”. Plants make phytols that break down similarly. There might be hundreds to thousands of breakdown products of these biochemicals. When these materials are run through a mass spectrometer, the device sorts them by chemical weight. Really good mass specs (like the ones I used to design for NASA) can even separate isotopes of carbon and hydrogen. Then a simple molecule like CH4 might have four or five Read More ›
Fats recovered from Ediacaran fossil, 558 mya, shows that animals then were “large,” “abundant”
Yes, you read that right and our physics color commentator Rob Sheldon explains why it was possible below. From ScienceDaily: Scientists from The Australian National University (ANU) and overseas have discovered molecules of fat in an ancient fossil to reveal the earliest confirmed animal in the geological record that lived on Earth 558 million years ago. The strange creature called Dickinsonia, which grew up to 1.4 metres in length and was oval shaped with rib-like segments running along its body, was part of the Ediacara Biota that lived on Earth 20 million years prior to the ‘Cambrian explosion’ of modern animal life. … “The fossil fat molecules that we’ve found prove that animals were large and abundant 558 million years Read More ›