Carbon dating dinosaur soft tissue
But the new data show that collagen was a better match to that of birds.That’s just what paleontologists, who consider birds to be descendants of extinct dinosaurs, would predict.Schroeter even went so far as to break down the mass spectrometer piece by piece, soak the whole thing in methanol to remove any possible contaminants, and reassemble the machine.“About the only thing that is the same [as the 2009 experiments] is the dinosaur,” Schweitzer says.But the claims were met with howls of skepticism from biochemists and paleontologists who saw no way that fragile organic molecules could survive for tens of millions of years, and wondered whether her samples were contaminated with modern proteins.Then last year Cappellini and Matthew Collins, a paleoproteomics expert at the University of York in the United Kingdom, and colleagues managed to identify protein fragments from 3.8-million-year-old ostrich egg shells, a claim that most of their colleagues found convincing.In a 2015 paper in , her group reported isolating fragments of eight other proteins from fossils of dinosaurs and extinct birds, including hemoglobin in blood, the cytoskeletal protein actin, and histones that help package DNA.Comparing those sequences from many different species could reveal evolution’s handiwork over geological time, much as studies of ancient DNA do today.
Schweitzer suggests that as red blood cells decay after an animal dies, iron liberated from their hemoglobin may react with nearby proteins, linking them together.
“I’m fully convinced beyond a reasonable doubt the evidence is authentic.” He calls the second study “a long shot that is suggestive.” But together, Cappellini and others argue, the papers have the potential to transform dinosaur paleontology into a molecular science, much as analyzing ancient DNA has revolutionized the study of human evolution.
Back in 20, Schweitzer reported in that she and her colleagues had isolated intact protein fragments from 65-million- and 80-million-year-old dinosaur fossils.
Schweitzer and Cappellini caution that while SR-FTIR is good at spotting the so-called amide chemical bonds that link successive amino acids in proteins, it can’t pin down exactly which protein is present, or the protein's sequence. This method also can’t rule out that the amide bonds are in other compounds, such as the epoxy used to assemble microscope slides.
“Synchrotron data is very powerful, but it’s limited,” Schweitzer says.
Search for carbon dating dinosaur soft tissue:
This crosslinking, she says, causes proteins to precipitate out of solution, drying them out in a way that helps preserve them. But he doesn’t think the process could arrest protein degradation for tens of millions of years, so he, for one, remains skeptical of Schweitzer’s claim. We can slow it down, but not by a lot,” Collins says.