Dinosaur blood and collagen discovered in fossil fragments [LINK] Scientists have discovered what appear to be red blood cells and collagen fibres in the fossilised remains of dinosaurs that lived 75 million years ago. Traces of the soft tissues were found by accident when researchers at Imperial College in London analysed eight rather shabby fossils that had been dug up in Canada a century ago before finding their way to the Natural History Museum in London. Sergio Bertazzo, a materials scientist at Imperial, had been working on the build up of calcium in human blood vessels when he met Maidment and asked if he could study some fossils with an array of electron microscope techniques. Bertazzo began to look at thin sections of the fossils. He began with the therapod claw. “One morning, I turned on the microscope, increased the magnification, and thought ‘wait - that looks like blood!’,” he said. While examining another fossil fragment, a piece of rib from some unidentified dinosaur, which had been sliced in two inside the microscope, he spotted bands of fibres, which further tests found to contain amino acids known that make up collagen, the protein-based material that forms the basis for skin and other soft tissues. More work is needed to be sure the features are genuine blood cells and collagen. The scientists now hope to scour more fossils for soft tissues, and then work out what sorts of burial and environmental conditions are needed for their preservation. “It may well be that this type of tissue is preserved far more commonly than we thought. It might even be the norm,” said Maidment, whose study appears in Nature Communications. “This is just the first step in this research.” A detailed study of the soft tissues could unravel some of the long-standing mysteries of dinosaur evolution. The dinosaurs evolved from cold-blooded ancestors, but their modern descendants are warm-blooded birds. When did the transition occur? Red blood cells may hold the answer. If collagen and red blood cells can survive for 75 million years, what about dinosaur DNA, bearing the genetic code to design, or potentially even resurrect, the beasts?