Biochemical signature, researchers say, are not necessarily lost in the process of fossilization:
In a new study published in the journal Science Advances, Yale researchers outline a novel approach to finding biological signals long thought to be lost in the process of fossilization. The new approach has already yielded valuable information about the soft shells that encased the first dinosaur eggs and shown that an ancient creature known as the Tully Monster was a very unusual vertebrate.
“What we’re discovering is that molecular, carbonaceous residues almost always preserve a microscopic clue within fossils,” said Jasmina Wiemann, a graduate student in the Department of Earth & Planetary Sciences at Yale and first author of the study. “Fossil organic matter is a wild mix of things, based on the chemical degradation products of original biomolecules.”
Working with Yale paleontologist Derek Briggs and Yale chemist Jason Crawford — both co-authors of the study — Wiemann analyzed the molecular composition of 113 animal fossils dating back 541 million years. It is the largest fossil data set to be analyzed by chemical means.
What they found was an abundance of soft tissues that fossilize into polymers. Recognizing these polymers and the soft tissues they represent may help researchers determine how various animals relate to each other in evolutionary history.
Yale University, “Biosignatures may reveal a wealth of new data locked inside old fossils” at ScienceDaily
Paper. (open access)
The big question is, will biosignatures just confirm the fossil record or bring Darwin’s house crashing down on his followers’ heads. The structure’s already wobbly.
The Tully Monster?
Every now and again, scientists discover fossils that are so bizarre they defy classification, their body plans unlike any other living animals or plants. Tullimonstrum (also known as the Tully Monster), a 300m-year-old fossil discovered in the Mazon Creek fossil beds in Illinois, US, is one such creature.
At first glance, Tully looks superficially slug-like. But where you would expect its mouth to be, the creature has a long thin appendage ending in what looks like a pair of grasping claws. Then there are its eyes, which protrude outward from its body on stalks.
Tully is so strange that scientists have even been unable to agree on whether it is a vertebrate (with a backbone, like mammals, birds, reptiles and fish) or an invertebrate (without a backbone, like insects, crustaceans, octopuses and all other animals). In 2016, a group of scientists claimed to have solved the mystery of Tully, providing the strongest evidence yet that it was a vertebrate. But my colleagues and I have conducted a new study that calls this conclusion into question, meaning this monster is as mysterious as ever.
Chris Rogers, The Conversation, “The mysterious ‘Tully Monster’ fossil just got more mysterious” at Phys.org
Apparently, the Yale conclusion that it is a vertebrate is disputed. The narrator of the video above tells us that the Tully Monster still has no fixed place in Darwin’s Tree of Life.
Hmm. Well, we’ll see what happens next with biosignatures.