Fossilised red blood cells found in 115m-year-old dinosaur’s bone, say scientists

Prof Kliti Grice with the fossilised remains of the Aratasaurus, a dinosaur that lived in Brazil 115m years ago. Photograph: Curtin UniversityView image in fullscreenProf Kliti Grice with the fossilised remains of the Aratasaurus, a dinosaur that lived in Brazil 115m years ago.

Prefer the Guardian on GoogleIt could be the opening of a Jurassic Park rip-off: scientists examining ancient dinosaur bones find what appear to be fossilised red blood cells, and traces of the molecule that gives the beast’s blood its distinctive crimson hue.

But that is what researchers are claiming to have discovered after analysing the hind leg bones of a small, meat-eating dinosaur called an Aratasaurus that lived and died in what is now north-eastern Brazil 115m years ago.

Electron microscope images of the dinosaur bones revealed small, round structures that resemble red blood cells in fine channels where blood vessels once ran, while chemical tests identified the presence of heme, the organic compound that allows haemoglobin in blood to carry oxygen around the body.

Such claims are controversial because biological tissues and molecules can break down fast, leaving little or no trace in ancient fossils. But if confirmed, it would open up entirely new avenues for scientists, allowing them to investigate dinosaur blood, metabolism and even their activity levels.

Os restos fossilizados do Aratasaurus foram descobertos em uma mina em 2008 e desde então têm sido mantidos no Museu Nacional do Brasil, onde pesquisadores continuam a estudá‑los.

Enquanto analisava os ossos da perna traseira do dinossauro, Grice avistou estruturas que se assemelhavam a glóbulos vermelhos.

The scientists’ suspicions that they were looking at red blood cells were bolstered when chemical tests came back positive for heme and its breakdown products. Tests also found traces of the amino acid building blocks for collagen, a key protein in connective and other tissues.

View image in fullscreenA portion the Aratasaurus’s hind limb. The remains were discovered in a mine in 2008 and have since been held in the National Museum of Brazil.

Photograph: Curtin UniversityIf the structures really are fossilised red blood cells, as the researchers contend, it raises the question of how they were preserved.

De acordo com Grice, um composto de manganês chamado hausmannite, que se formou dentro e ao redor das células sanguíneas, pode ter dado uma mão amiga ao estabilizá‑las antes da fossilização.

The same process might have helped preserve the amino acids, she added. The study appears in Proceedings of the National Academy of Sciences.

The work is already stoking debate. Prof Mary Schweitzer at North Carolina State University in the US, who has discovered remnants of blood vessels and soft tissues in dinosaur fossils, is not convinced Grice and her colleagues have found red blood cells.

Uma das razões para a dúvida dela é que as hemácias vermelhas do dinossauro deveriam apresentar um “nuclear bulge”, fazendo-as parecer domo em ambos os lados. As estruturas encontradas por Grice são côncavas, sugerindo que podem ser algo diferente.

Schweitzer was more persuaded by the discovery of heme and collagen amino acids in the bone and said there was so much more to learn from exceptionally well-preserved fossils.

Schweitzer acrescentou: “A sabedoria convencional em paleontologia de que todos os orgânicos endógenos desapareceriam em um milhão de anos ou menos está sendo desafiada rotineiramente, e continuará a ser, à medida que abordagens tecnológicas para espécimes paleontológicos são aplicadas de forma mais rotineira.”.

Another question the research raises is what other biological material might lurk in fossils collections around the world. On this, Grice urges extreme caution, adding that her work does not imply that large biological molecules such as proteins or DNA live on in ancient fossils.