"When researchers scraped tiny pieces off the fossil and looked at them under an electron microscope, they found tiny structures that look a lot like collagen fibers present in our own ligaments, tendons, and bones."
The photo above, from a new study published today in Nature Communications and led by Sergio Bertazzo of Imperial College London, shows an extremely zoomed-in view of a 75-million-year-old theropod claw, taken from the London Natural History Museum's collection. When researchers scraped tiny pieces off the fossil and looked at them under an electron microscope, they found tiny structures that look a lot like collagen fibers present in our own ligaments, tendons, and bones.
“You sure? They continued describing tiny fibers which do seem to be present in that photo...”
Yes. In the original report it is listed as Fig. 2.c, Emu blood.