By utilizing a technique known as Resonance Raman Spectroscopy, paleontologists have discovered hemoglobin remnants in bone extracts of two dinosaur species, Brachylophosaurus canadensis and Tyrannosaurus Rex, confirming that these molecules are original components from these dinosaurs.
Bright field images depict ostrich containers soaked in hemoglobin under oxygenation conditions, as compared to those under deoxygenation conditions. Brachylophosaurus canadensis (a) and Tyrannosaurus Rex (d) bone. Scale bar – 0.5 mm in (AC) and 0.2 mm in (D). Image credit: Long et al., doi: 10.1098/rspa.2025.0175.
Soft tissue, which maintains some of its original properties, has been recovered from numerous Mesozoic vertebrate sites.
Specifically, the chemical composition of soft tissues from the two non-bird dinosaur species, Brachylophosaurus canadensis and Tyrannosaurus Rex, has been studied extensively over the last 20 years.
All evidence supports the hypothesis that these tissues are endogenous to once-living dinosaurs.
In a recent study, Professor Hans Harren and his team from North Carolina State University employed tissue resonance Raman (RR) imaging to verify the presence of hemes, globin proteins, and minerals linked to iron oxidation.
“Raman spectroscopy essentially utilizes light waves to identify the energetic ‘fingerprint’ of a molecule,” stated Professor Harren.
“The resonant Raman method employed here enhances that process through light that has been pre-conditioned to resonate with the molecule of interest, ensuring that only that specific type of molecule resonates.”
“Moreover, this molecular resonance produces a stronger signal, enabling that signal to effectively ‘overwhelm’ those from other types of molecules.”
“This powerful signal allows us to discover needles (hemoglobin remnants) in haystacks (complex fossils), revealing how this molecule has transformed from its living conditions and indicating that chemically altered molecules have endured over deep time.”
The researchers utilized RR imaging to focus on molecules bound to hemoglobin.
They analyzed samples from Brachylophosaurus canadensis, Tyrannosaurus Rex, ostrich bones (Struthio camelus), and human blood.
“The elevated signal indicates hemoglobin presence, while fluctuations in signal may lead to goethite formation from iron within hemoglobin as it deteriorates,” Professor Harren noted.
“We can also pinpoint damage to structures such as the hem ring.”
“This phenomenon was observed in both contemporary and ancient samples.”
The findings also eliminate the possibility of sample contamination.
“Raman spectroscopy reveals existing molecular bonds, but because molecular bonds are non-exclusive, they can derive from various sources.”
“RR imaging identifies both binding and structure. We can confirm that the heme is intact and still affiliated with the hemoglobin protein, distinguishing it as originating from an animal, or in this situation, a dinosaur, since contaminants like bacteria lack specific binding.”
Furthermore, scientists emphasize that comprehending the deterioration and alterations of heme over time can shed light on fossilization processes and explain the longevity of molecules over millions of years.
“The most significant discovery is our ability to demonstrate that hemoglobin fragments can endure for thousands of years, while also gaining valuable insights into the evolution of these molecules,” Professor Harren remarked.
“Goethite is a bio-related mineral crystal, meaning it forms from biological influences.”
“However, I was unaware that it could bind and stabilize protein fragments.”
“Hemes are found in deposits much older than dinosaurs, reinforcing our understanding of their durability,” Professor Schweitzer stated.
“Understanding the preservation of hemoglobin and the role of heme in this process is crucial for deciphering how such ancient molecules persist over time.”
The study will be published in Proceedings of the Royal Society A.
____
BJN Long et al. 2025. Resonant Raman confirms the preservation of partial hemoglobin in dinosaur fossils. Proc. R. Soc. A 481 (2321): 20250175; doi: 10.1098/rspa.2025.0175
Source: www.sci.news
