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.
