Scientists have found chemical traces of blood-derived molecules in 115-million-year-old dinosaur bones, providing the first definitive chemical confirmation of a molecule derived from hemoglobin in fossilized dinosaur red blood cells. The discovery, led by Curtin University researchers, suggests that some fragile biomolecules can survive far longer than previously believed and could influence both the study of prehistoric animals and the search for evidence of ancient life beyond Earth.
Blood molecules preserved in dinosaur bones
An international team found chemical evidence of fossilized red blood cells and blood molecules in the remains of Aratasaurus museunacional, a carnivorous theropod dinosaur discovered in northeastern Brazil. The study, published in Proceedings of the National Academy of Sciences, also identified amino acids associated with collagen, an important structural protein found in bones and other connective tissues.
Previous studies had identified structures resembling blood cells in ancient fossils, but scientists had not conclusively demonstrated that these structures contained specific molecular remnants of blood. The new research provides direct chemical evidence of heme, a component of hemoglobin—the protein that enables red blood cells to transport oxygen.
When the researchers examined the dinosaur’s limb bones, they found large numbers of petrified red blood cells in the vasculature, the small passageways where blood vessels once existed. The presence of heme-derived molecules indicates that the fossils retain molecular remains of ancient blood.
The findings also show that biological materials once considered too fragile to survive for millions of years can remain detectable under exceptional conditions.
The research was led by John Curtin Distinguished Professor Kriti Grice, founding director of Curtin University’s WA Center for Organic Isotope Geochemistry and an Australian Research Council Awarded Fellow.
“It is surprising that we have detected intact heme-derived molecules in 115-million-year-old red blood cells. This is a truly groundbreaking discovery,” Professor Grice said.
“This not only expands the known blood fossil record, but also provides a direct molecular window into the physiology of long-extinct animals, so we may better understand them and the world they lived in.”
How dinosaur blood survived for 115 million years
The exceptional preservation appears to be linked to hausmannite, a mineral that helped stabilize the fossilized blood cells and preserve their molecular components, including collagen-related amino acids, over geological timescales.
In effect, the mineral may have created a natural time capsule containing microscopic evidence of dinosaur life long after the animal’s death.
The circumstances of burial may also have been important. Researchers suspect the animals were rapidly covered in sediment in an environment with little oxygen and substantial microbial activity. Such conditions may help preserve biological materials that would normally degrade and disappear.
The international research effort involved scientists from Curtin University’s School of Earth and Planetary Sciences, the Marine Research and Development Agency, the Brazilian National Museum, Cariri Regional University and Johns Hopkins University.
New possibilities for molecular paleontology
The discovery challenges the long-held assumption that blood-related molecules, particularly those derived from hemoglobin, cannot survive for such long periods.
It confirms the survival of ancient blood components while raising the possibility that other fossils contain molecular information overlooked by traditional tests. This could allow researchers to investigate the evolution of blood, metabolism and activity levels in ancient animals.
“These findings challenge the long-held assumption that certain biomolecules, such as hemoglobin, cannot survive for long periods of time,” Professor Grice said.
“This opens up exciting new avenues in paleontology at the molecular level, allowing us to investigate the evolution of blood, metabolism and even activity levels in ancient animals.”
Such information could help scientists understand how extinct animals functioned, including aspects of their metabolism and physiology that are difficult to reconstruct from bones alone.
Implications for the search for ancient life
The significance of the discovery could extend beyond dinosaur research. Understanding how fragile biological structures survive for millions of years may help scientists identify traces of ancient life in other extreme environments, including beyond Earth.
Professor Martin van Kranendonck of Curtin University’s School of Earth and Planetary Sciences said the findings were changing researchers’ understanding of how molecular structures can be preserved over vast timescales and under harsh conditions.
These insights could be valuable to astrobiology, the study of the possibility of life elsewhere in the universe. If biomolecules or their chemical signatures can persist for more than 100 million years under suitable conditions, scientists may need to reconsider where and how they search for evidence of ancient life.
“This research illustrates how collaborative efforts across institutions, continents and scientific disciplines can unlock extraordinary insights into ancient life,” Professor van Kranendonck said.
The research was supported by the 2021 Australian Research Council Laureate Fellowship awarded to Professor Grice.
The study is titled “Heme signature of calcified red blood cells in blood vessels of a 115-million-year-old dinosaur bone” and was published in Proceedings of the National Academy of Sciences.
Source: www.sciencedaily.com
