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Meaty Finds: Two Studies Claim to Have Isolated Dinosaur Proteins

Scientists have long thought soft tissues couldn’t survive over millennia—but new research suggests that isn’t the case

This 195-million-year-old rib bone may still have bits of protein clinging to its crevices. (Robert Reisz)
smithsonian.com

Though fossils may resemble the creatures that once roamed the earth, all that remains are remnants of these once magnificent organisms, including casts (like footprints) or mineralized bones. The actual meat was thought to be long gone—too delicate to survive the passage of millions of years or the heat and pressure ancient animal remains often undergo. But two recently released studies are upending that idea, suggesting that small amounts of protein from dinosaurs may still cling to their fossilized bones.

The first study was led by paleontologist Mary Schweitzer at North Carolina State University—and this was not her first supposed meaty find. In 2007 and 2009 Schweitzer published papers, in which she and her team claim to have isolated collagen from dinosaur fossils, reports Robert F. Service for Science. At the time, however, the studies were met with skepticism. Many scientists believed the proteins were just modern contamination.

In the years since, laboratory techniques have considerably advanced. Researchers have even extracted protein from an ostrich egg that is millions of years old, reports Service, suggesting that some proteins persist over the millenia.

So Schweitzer decided to repeat her 2009 experiment. “Mass spectrometry technology and protein databases have improved since the first findings were published, and we wanted to not only address questions concerning the original findings, but also demonstrate that it is possible to repeatedly obtain informative peptide sequences from ancient fossils,” Elena Schroeter, a postdoctoral student working with Schweitzer and first author of the study in the Journal of Proteome Research says in a press release.

The researchers examined the thigh bone of a duck-billed dinosaur, Brachylophosaurus canadensis, that lived in the area of modern-day Montana 80 million years ago. Going to great pains to avoid contamination, they left a meter of sediment around the fossil and did not use glues or preservatives. Service reports that the team even soaked every piece of the mass spectrometer in methanol to clean it.

In this latest analysis, the team identified eight protein fragments, two of which matched proteins identified in the 2009 study. “If [both sets] are from contamination, that’s almost impossible,” Schweitzer tells Service.

According to the press release, the collagen collected is similar to that found in modern crocodilians and birds. The researchers are not sure exactly what process allows the proteins to survive over millions of years. But some skeptics are starting to warm up to the idea that these are not contamination. Enrico Cap­pellini of the University of Copenhagen’s Natural History Museum of Denmark, who was doubtful of Schweitzer’s previous work tells Service, “I’m fully convinced beyond a reasonable doubt the evidence is authen­tic.”

The second recent announcement, however, was met with mixed reviews. The study, published this week in the journal Nature Communications, documents evidence of protein in the crevices of a rib from a 195-million-year old Lufengosaurus, a long-necked plant-eating dinosaur, reports the Agence France-Presse.

The researchers examined the chemical content of the bone using a photon beam at Taiwan’s National Synchrotron Radiation Research Center. According to a press release, the scan revealed that tiny canals inside the bone contained hematite crystals, likely from red blood cells and may contain collagen proteins from blood vessels.

Stephan Brusatte, a paleontogoist at the University of Edinburgh, tells Helen Briggs at the BBC that he’s convinced by the work. “To find proteins in a 195-million-year-old dinosaur fossil is a startling discovery,” he says. “It almost sounds too good to be true, but this team has used every method at their disposal to verify their discovery, and it seems to hold up.”

But not all scientists so enthusiastic about the research. “Synchrotron data is very powerful, but it’s limited,” Schweitzer tells Service. “I would like to have seen confirmatory evidence.” She says she hopes the team will work with other specialists to confirm the find.

Service reports that the discovery of proteins in ancient bones could help scientists map the evolutionary relationships between different dinosaurs and other extinct species. The proteins, however, do not contain any DNA.

Sorry, everyone. Still no Jurrasic Park on the horizon.

About Jason Daley

Jason Daley is a Madison, Wisconsin-based writer specializing in natural history, science, travel, and the environment. His work has appeared in Discover, Popular Science, Outside, Men’s Journal, and other magazines.

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