Watch the birdy (Image: Moviestore/REX Shutterstock)

Jurassic Park saw dinosaurs brought back to life based on DNA preserved in the gut of a blood-sucking mosquito entombed in amber. Now we have found what appears to be real dinosaur blood inside a bog-standard fossil bone.

“We stumbled on these things completely by chance,” says Susannah Maidment of Imperial College London, whose team was trying to study bone fossilisation by cutting out tiny fragments of fossils.

Instead, they found blood-like cells and collagen from 75-million-year-old dinosaur fossils – 10 million years before T. rex appeared.


Although the cells are unlikely to contain DNA, those extracted from better preserved fossils using the same technique may do so, she says.

And even without DNA, soft tissue cells and molecules could help us learn much more about dinosaur physiology and behaviour, the team says. For example, the physical size of blood cells can reveal insights into metabolism, and the possible transition from a cold to warm-blooded existence.

So far, such soft flesh tissues were only ever found in serendipitous fossils preserved in exceptionally rare circumstances, for example, by being frozen in ice or in a dry environment free of microbes that would otherwise break down the flesh, says Maidment.

Blood cells came from this claw (Image: Laurent Mekul)

“But the fossils we looked at were not rare at all,” she says. They were ordinary bones collected from the surface at the well-known Dinosaur Park Formation in Canada.

To study fossil bones, the team borrowed a medical research technique based on a focussed ion beam, that is giving clues to how blood vessels become calcified and cause heart attacks. Their intention was to study how natural bone minerals fossilise, and what happens when collagen decays in dinosaur bones.

“This beam works like a knife, with a microscopic robotic arm bearing a needle that enables you to cut out fragments of interest,” says Sergio Bertazzo, also of Imperial College London, who co-led the investigation.

Bird-like collagen fibres (Image: Sergio Bertazzo)

Three-dimensional examinations of the blood-like cells under an electron microscope revealed that they had nuclei, so human red blood cells could not have contaminated the sample, because they have no nuclei.

And when Maidment analysed the chemical composition of the red blood cells with a technique called mass spectrometry, the spectrum was surprisingly similar to that of blood taken from a living bird, an emu, adding further evidence to it being from a dinosaur.

Maidment is now hoping to investigate more samples. “We want to understand how this preservation can occur, how far back in time it happens, and what type of rock it happens in,” she says.

The discovery was welcomed by John Asara of Harvard Medical School, whose team reported in 2007 finding collagen in a 68-million-year old T. rex and in an 80-million-year old brachylophosaurus fossil. Asara says this field of science has been barely tapped.

“Papers like this do much to advance the field, by showing that fossils are more than ‘just rocks’, and opening the door to the possibility that materials persist in ancient fossils that were not thought possible only a few years ago,” says Mary Schweitzer of North Carolina State University in Raleigh, who reported extracting blood from T. rex in 2009. “[It also] seems to indicate, like our own findings, that this is not necessarily an exceedingly rare occurrence.”

Journal reference: Nature Communications, DOI: 10.1038/ncomms8352