Dinosaurs fossils, we've all been taught, consist of bone — their flesh, skin, and organs having decayed long ago. But a new discovery might upend that assumption: Scientists have found evidence of blood cells with the protein intact in eight fossils which were not even particularly well-preserved.
Soft-tissues have been discovered in dinosaurs before, but the results were controversial. In fact, some experts still believe it's contamination. But a new study published in Nature Communications uses a high-tech tool to peer more clearly at fossils than ever before. Robert F. Service describes the technique for Science:
[Sergio] Bertazzo, an expert on how living bones incorporate minerals, uses a tool called a focused ion beam to slice through samples, leaving pristine surfaces that are ideal for high-resolution imaging studies. He teamed up with Maidment to apply the technique to eight chunks of dinosaur toe, rib, hip, leg, and claw.
What they found shocked them. Imaging the fresh-cut surfaces with scanning and transmission electron microscopes, "we didn't see bone crystallites" as expected, Maidment says. "What we saw instead was soft tissue. It was completely unexpected. My initial response was these results are not real."
The team found round structures resembling red blood cells and strands resembling the protein collagen. When they ran a chemical analysis, the blood cells were similar to that of emus' (a relative of dinosaurs) and the collagen seemed to be made up of amino acids known to be common in the protein. This isn't necessary slam-dunk proof yet, but it's tantalising.
The discovery is so exciting because the fossils in this study were utterly unremarkable. If the results hold up, it could mean soft tissues may be preserved in many run-of-the-mill fossils. But no — I know what you're thinking — DNA is still more fragile than proteins, so don't expect Jurassic Park yet.
Below: Amorphorous carbon-based material (left) and red blood cell-like structures (right).
Top image: Scanning electron micrograph of the dinosaur fossil, showing what may be strings of collagen. Bertazzo et al