Ediacaran

MOVE over, Dickinsonia. This 558-million-year-old creature was named the earliest known animal last year, but New Scientist can now exclusively reveal one that existed even earlier – by more than 40 million years. (paywall) Graham Lawton, “Exclusive: 600-million-year old blobs are earliest animals ever found” at New Scientist Note: They are described at New Scientist above as “carnivorous comb jellies” but all known comb jellies are carnivorous so it will be interesting to learn more about what that “earliest known animal” was eating. Last year, we learned Intro: A strange soft-bodied sea creature that lived over half a billion years ago may have been the first animal species on Earth, fossil evidence suggests. The first large complex organisms – known Read More ›

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 ›

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 ›

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 ›

News from the Ediacaran era (600 – 542 million years ago), when many animals were genuinely hard to distinguish at first from plants, sharpens the question: So-called Ediacaran organisms have puzzled biologists for decades. To the untrained eye they look like fossilized plants, in tube or frond shapes up to 2 meters long. These strange life forms dominated Earth’s seas half a billion years ago, and scientists have long struggled to figure out whether they’re algae, fungi, or even an entirely different kingdom of life that failed to survive. Now, two paleontologists think they have finally established the identity of the mysterious creatures: They were animals, some of which could move around, but they were unlike any living on Earth Read More ›

From ScienceDaily: The research, led by the University of Cambridge, found that the most successful organisms living in the oceans more than half a billion years ago were the ones that were able to ‘throw’ their offspring the farthest, thereby colonising their surroundings. The results are reported in the journal Nature Ecology and Evolution. Prior to the Ediacaran period, between 635 and 541 million years ago, life forms were microscopic in size, but during the Ediacaran, large, complex organisms first appeared, some of which — such as a type of organism known as rangeomorphs — grew as tall as two metres. These organisms were some of the first complex organisms on Earth, and although they look like ferns, they may Read More ›