Aratasaurus museunacionali fossil blood cell remains, Digi Mart USA News (Brazil): A dinosaur that lived in South America about 115 million years ago has become the subject of a scientific discovery that could change the way fossils are studied. Researchers identified microscopic structures resembling red blood cells and chemical signals related to blood components in the bones of its legs.
The find corresponds to a specimen of Aratasaurus museunacionali, a carnivorous dinosaur whose remains were discovered in Brazil. The research, published in November 2026 in the journal Proceedings of the National Academy of Sciences, adds new evidence about the preservation of biological material over millions of years.
The fossil remains belong to an animal that lived during the Early Cretaceous, long before the disappearance of non-avian dinosaurs. The specimen was approximately 3.1 meters long and weighed about 34 kilograms.
Researchers estimate it died when it was around four years old.
Its bones were discovered in 2008 in a gypsum mine in the Brazilian state of Ceará. During analysis of the samples, specialists identified small oval structures within vascular canals, the spaces through which blood originally circulated.
They also detected chemical signals associated with the heme group, an iron-containing molecule that forms part of hemoglobin.
The combination of these elements led the research team to propose that some structures could correspond to mineralized remains of red blood cells. However, the specialists clarified that this is not fresh blood or cells preserved in their original state.
For decades, it was considered that many biological components disappeared completely after relatively short periods in geological terms. Modern techniques, however, make it possible to identify chemical traces and microscopic structures in much older fossils.
Researchers believe the conditions in which the dinosaur was buried may have favored the preservation of these materials. Contact with microbial communities and mineralization processes may have helped preserve some signals related to the original tissues.
Despite the results, other specialists questioned whether the observed structures can definitively be identified as red blood cells. The research also did not recover dinosaur DNA, so the discovery does not represent a possibility of cloning.
Its significance lies in offering new tools for studying the physiology of extinct animals and understanding how certain biological components can leave traces for millions of years.
