Microscopic images of structures resembling red blood cells from the fossilized limb bone of the theropod dinosaur Aratasaurus, taken at a laboratory at Curtin University in Perth, Western Australia.
A 3D model of a red blood cell-like structure found during the discovery. Curtin University
Traces of prehistoric blood could reveal unprecedented clues about dinosaur biology, but they’ve been notoriously difficult to confirm. Now, researchers studying a 115 million-year-old dinosaur bone say they’ve found the strongest evidence yet of red blood cells in a fossil.
Tissues, cells and other soft biological samples rarely ever survive the fossilization process and thus make for controversial discoveries. A few previous studies, dating back to the late 1990s, have reported structures resembling red blood cells in dinosaur and other reptile fossils, but researchers have fiercely debated their legitimacy.
The new study, published Monday in the journal Proceedings of the National Academy of Sciences, used a combination of new microscopic imaging and chemical analyses to find not only microscopic structures resembling red blood cells preserved within the dinosaur bone, but also chemical evidence of heme — a molecule in hemoglobin, the protein in red blood cells that carries oxygen. According to the study’s authors, it is the first time heme has been detected in situ, or within the structures themselves, in a dinosaur fossil.
A portion of the fossilized remains of the right hind limb of the theropod dinosaur Aratasaurus, seen at Museu de Paleontologia Plácido Cidade Nuvens, Santana do Cariri, Ceará, Brazil.
