Particle Accelerators Are Changing The Way We Look At Ancient Turds

Particle Accelerators Are Changing The Way We Look At Ancient Turds

There’s so much you can learn about animals, their lifestyles, and the world they interacted with based on what shows up in their poo. Especially if the poo is over 200 million years old.

A fossil poop (Image:Poozeum/Wikimedia Commons)

Most of the methods used to look at fossilised poo, more commonly called coprolites, are fairly outdated. Scientists mainly use two-dimensional imaging techniques that require cutting literal slices of the sample to look at them up close. Three-dimensional imaging methods in the lab might miss the smallest features like hairs or insect legs. But a team of Swedish scientists have a better way to reveal the poo’s secrets: Particle accelerators.

Accelerating particles is for more than just dense particle physics. A special type of accelerator, called a synchrotron, sends electrons racing around an enormous racetrack, in this case the 844m-round European Synchrotron Radiation Facility. Every time the electrons change direction, they let out high-powered X-rays that shoot down a beam pipe where the poop awaits its close-up.

Image: Hendrich/Wikimedia Commons

The new paper marks the first time that researchers have imaged fossilised poo with this specific kind of accelerator imaging, called “propagation phase-contrast synchrotron microtomography”. Once the X-rays actually hit the poop, they’re collected and used to create an image based on what light was and wasn’t absorbed. The phase contrasting part just means that the image can be even further sharpened by comparing how the alignment of the light waves shift. The increased resolution is important.

“We expect that many rare and new organisms will be discovered with this increased ability to study the inclusions by [propagation phase-contrast synchrotron microtomography],” the authors wrote in the study published last week in Scientific Reports.

Poop number one (Image: Qvarnström et al, Sci. Reports (2017))

But you’re probably sick of the experiment methods crap — what about the crap crap? One poop, a part of a several-centimetre-long coil from a big swimming meateater, contained pieces of an ancient fish and bivalves. Pieces of the fish’s pelvic tract remained intact despite digestion. Another several-centimetre-long poop (not coiled) clearly contained parts of a beetle, and was maybe made by some sort of dog-sized insectivorous lizard.

Other researchers thought this was a cool paper. “Analysing coprolites at this level of detail opens up an entire new universe of research possibilities for those interested in reconstructing the paleobiology of extinct organisms,” NYU anthropology professor Terry Harrison told Gizmodo in an email. “The tricky part is going to be identifying the producers of the coprolites, which will inevitably be the critical part of the equation.” Otherwise, he thought the authors did an “exemplary job” and used “reasoned detective work” to make their conclusions.

Poop number 2 (Qvarnström et al, Sci. Reports (2017)

But this scat story is far from over.

“Getting information from coprolites is difficult,” Distinguished Professor of Paleontology Robert Reisz from the University of Toronto Mississauga told Gizmodo in an email. He pointed out that the arguments presented in this “nice piece of work” are reasonable but speculative. “Its scientific impact is modest because it only indicates that larger fish were eating smaller fish, and that a fairly large terrestrial vertebrate ate beetles as part of its diet (but necessarily only arthropods).”

And, as Harrison said, “to complete the story, one would need to know who was responding to the call of nature.”

But thanks to physics, scientists will now be able to understand old crap like never before.

[Scientific Reports]