Deep within the fine channels that once carried blood through a small predatory dinosaur's hind limb, researchers report finding traces of heme, the iron-bearing compound that lets blood carry oxygen, in a bone roughly 115 million years old. It is a rare kind of memory left by a creature that lived in what is now northeastern Brazil, and it arrives as a reminder that the physical past sometimes keeps more than we expected. Scientists are careful to note what this does not mean: the molecules are not proof of intact DNA, and the story of ancient life is still being read one faint trace at a tim
Heme Detected in 115-Million-Year-Old Dinosaur Bone, Reviving Debate on Molecular Survival
Chemical tests showed heme inside the shapes
Mark
So what exactly did they find in this bone?
Mimi
Oval shapes inside the microchannels of a theropod's hind limb, and chemical tests showing heme in those shapes. Heme is the iron compound in haemoglobin.
Mark
Why does heme matter so much?
Mimi
The authors say it's the first in situ detection of heme in a dinosaur fossil, and that it challenges the idea that biomolecules can't survive deep time.
Luke
Careful, though. "First" and "strongest evidence yet" are the authors' own framing. What's confirmed is the paper's reported detection of heme.
Mark
And the shapes? Are they red blood cells?
Mimi
That's the dispute. Mary Schweitzer says non-mammalian red blood cells usually keep nuclei and have a bulge, and these concave shapes don't fit.
Luke
So the cell identification is contested, even by someone who praised the methods. Her objection is on the record, but we don't have a settled answer.
Mark
How did the molecules last 115 million years?
Mimi
The team points to quick burial in an oxygen-poor setting and the mineral hausmannite.
Luke
That's their belief, not a demonstrated mechanism. And nothing here says DNA survived; the authors say so themselves.
Mark
What happens next?
Mimi
They say the approach could be used on other fossils, including those already sitting in museum collections.
Le Pouls
- A chemical signature of heme has surfaced inside a 115-million-year-old dinosaur bone, challenging assumptions about what can survive deep time.
- Oval structures in the bone's microchannels look like red blood cells, but a leading paleontologist says their concave shapes do not match the expected pattern.
- The team credits rapid burial in oxygen-poor sediment and the mineral hausmannite with preserving the molecules, and is pressing to test the method on other fossils.
- Museum collections worldwide may hold similar hidden molecular data, and the debate over what these shapes truly are remains unresolved.
Deep within the fine channels that once carried blood through a small predatory dinosaur's hind limb, researchers report finding traces of heme, the iron-bearing compound that lets blood carry oxygen, in a bone roughly 115 million years old. It is a rare kind of memory left by a creature that lived in what is now northeastern Brazil, and it arrives as a reminder that the physical past sometimes keeps more than we expected. Scientists are careful to note what this does not mean: the molecules are not proof of intact DNA, and the story of ancient life is still being read one faint trace at a time.
Inside the hind limb of a small predatory dinosaur, in channels so fine they once carried blood, researchers say they have found something that was never supposed to last: the iron compound that lets blood carry oxygen. The bone belongs to Aratasaurus museunacionali, a theropod whose fossil was unearthed in northeastern Brazil in 2008, and it is about 115 million years old.
A team led by Prof. Kliti Grice of Curtin University examined the bone's microchannels with microscopy and chemistry. They found oval shapes resembling red blood cells, and chemical tests showed those shapes held heme. The researchers believe this is the first time heme has been detected in a dinosaur fossil while still in place within the bone, and they see it as the strongest evidence yet that red blood cells can endure fossilisation. Their explanation rests on quick burial in low-oxygen conditions and the presence of hausmannite. Grice called it a landmark result, and the authors argue that museum collections may hold similar overlooked molecular records.
Not everyone is convinced. Prof. Mary Schweitzer questioned whether the shapes truly resemble non-mammalian red blood cells, which usually keep their nuclei and show a distinctive bulge, and she noted the concave forms here do not fit. Still, she praised the team's multiple analytical methods. The authors themselves caution that the findings do not suggest DNA survived, and that they are far from a "Jurassic Park" scenario. What comes next is whether other laboratories can reproduce the detection and whether the identity of those oval shapes is finally settled.
Inside the hind limb of a small predatory dinosaur, in channels so fine they once carried blood, researchers say they have found the remains of something that was never supposed to last: the iron compound that lets blood carry oxygen. The bone is about 115 million years old.
The animal is Aratasaurus museunacionali, a small theropod. Its fossil was found in northeastern Brazil in 2008. A paper on the new work was published Monday in the Proceedings of the National Academy of Sciences, from a team led by Prof. Kliti Grice of Curtin University.
Using microscopic and chemical analysis, the team looked inside the bone's microchannels, the passages that transported blood during the animal's life. There they found oval shapes resembling red blood cells. Chemical tests then showed that these shapes contained heme, the iron-bearing compound found in haemoglobin that is responsible for carrying oxygen.
The authors say this is the first time heme has been detected in a dinosaur fossil in situ, meaning in place within the bone rather than extracted from it. They describe it as the strongest evidence yet that red blood cells can survive fossilisation.
The team offers an explanation for how the material endured. They believe two factors played a part: rapid burial in an environment low in oxygen, and the presence of hausmannite, a manganese oxide mineral. Grice called the result a landmark discovery and said it challenges long-held assumptions that biomolecules such as haemoglobin cannot survive across deep time.
The researchers argue the method could be used on other fossils. In their view, museum collections around the world may hold molecular information that has never been investigated.
Not every expert is persuaded. Prof. Mary Schweitzer of North Carolina State University questioned whether the structures truly match the red blood cells of non-mammalian animals, which typically keep their nuclei and show a distinctive bulge. The concave shapes found in the Brazilian bone, she said, do not fit that profile. She nonetheless praised the team's use of multiple analytical techniques and called the work an exciting advancement.
The authors themselves put limits on the claim. Their findings, they stress, do not imply that DNA survived, and they are a long way from "Jurassic Park." What to watch now is whether other laboratories can repeat the heme detection in other fossils, and whether the argument over what the oval shapes actually are gets settled.
Citations marquantes
This really is a landmark discovery.— Prof. Kliti Grice, Curtin University
The concave shapes found do not fit the profile of non-mammalian red blood cells, though the multi-technique approach is an exciting advancement.— Prof. Mary Schweitzer, North Carolina State University (paraphrased)
Envie de l'histoire complète ?
Lire l'original sur Geo News ↗
Science & Space