Weird animal forms: possible first animal (Introduction)

by David Turell , Wednesday, January 23, 2019, 19:52 (2130 days ago) @ David Turell

It was found to have cholesterol, an animal protein:

https://bgr.com/2018/09/20/dickinsonia-plant-or-animal-study-research/

"Dickinsonia lived over half a billion years ago, back when plants and animals were really nothing like they are today. Many of the organisms of the day were flat and ribbed and, well, boring. This makes it surprisingly hard to tell what finds in the fossil record are animals and which are plants. A new study says it’s now likely Dickinsonia was one of the earliest animals, but that’s far from a sure thing.

"To get it out of the way: Dickinsonia, if it was indeed an animal, would definitely be the oldest known animal on Earth. A new paper published in Science focuses on one particular Dickinsonia fossil that was analyzed in depth. In the fossil the researchers discovered something surprising: cholesterol. Tiny molecules of cholesterol were found in the fossil and, the researchers believe, it’s all the proof we need to declare the organism to be a true animal rather than a plant or fungus.

“"The fossil fat molecules that we’ve found prove that animals were large and abundant 558 million years ago, millions of years earlier than previously thought,” associate professor Jochen Brocks of the ANU Research School of Earth Sciences said in a statement.

“'Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Edicaran Biota were: giant single-celled amoeba, lichen, failed experiments of evolution or the earliest animals on Earth. The fossil fat now confirms Dickinsonia as the oldest known animal fossil, solving a decades-old mystery that has been the Holy Grail of palaeontology.'”

Comment: Animal metabolism had to appear at some ancient point around 600 million years ago.