New research from scientific research team at National Synchrotron Radiation Research Center (NSRRC) in Taiwan and scientist in Canada provides the first evidence that collagen proteins have been preserved within the 195-million-year-old rib of the sauropodomorph dinosaur Lufengosaurus. The study appears in the January 31 issue of the journal Nature Communications.
The scientific research team members include Yao-Chang Lee (NSRRC), Cheng-Cheng Chiang (NSRRC), Pei-Yu Huang (NSRRC), Chun-Chieh Wang (NSRRC) and Ching-Iue Chen (NSRRC), Chao-Yu Chung (National Chiao Tung University), Timothy D. Huang (National Chung Hsing University), Rong-Seng Chang (National Central University) and Chen-Hao Liao (Tosun Public Interests Foundation) and Robert R. Reisz (University of Toronto Mississauga).
Non-destructive In-situ synchrotron-based infrared microspectroscopy identifying ancient collagen within dino ribs
In-situ spatially-resolved synchrotron-based infrared microspectroscopy (SR-IMS) has successfully demonstrated the non-destructive detection of type I collagen fragment remnants within dino rib fossil slide of thickness of 30 μm without decalcifying the sample of rib fossil. The identification of type I collagen within Haversian canals in Lufengosaurus rib fossil is identified and confirmed based on the characteristic infrared absorption of standard sample of type I collagen, being the major component of blood vessel.
“In-situ Synchrotron-based technology coupled non-destructive μ-FTIR analysis utilizes for identifying the collagen and surrounded material within vascular canals of fossil, which would gave clues for unfolding the possible preservation mechanism of collagen in the 195 Myr dino ribs,” Yao-Chang says.
Endogenous Hematite cementation during the early diagenesis could be the critical process in preserving the collagen for 195 Myr
Organic remnant within the hundred-million-year-old bone fossils is rare. In the last two decades, several scientific reports had successfully demonstrated that degraded collagen remnants were found in ten-million-year-old dino fossils using the technologies of mass spectroscopy and electron microscopy. The Taiwan-Canada research team employed the Synchrotron technologies at NSRRC to investigate the substance in situ, identified as collagen type I, preserved within the tiny vascular canals of the 195 Myr rib fossil where blood vessels and blood would be in the living dinosaur. The collagen was found together with lots of micro-sized, hemi-spherical hematite particles. Hematite (α-Fe2O3) is a mineral that can be formed from the iron ions in hemoglobin, the oxygen-transport protein in red blood cells and other iron-rich protein like lactoferrin.
Yao-Chang and his colleagues believe that these hematite particles were derived from the hemoglobin of original blood and iron-rich protein of the dinosaur, and that initial iron (II) acted as the antioxidant and anti-bacterial, and the following formation of hematite cementation played a role of isolator for preventing the collagen in the vascular canals from further degradation or exogenous replacement. These collagen are probably remnants of the blood vessels that supplied blood to the bone cells in the living dinosaur.
In the early stage of this research, many erythrocyte-like dark particles and lacunae were already found within the vascular canals of the dino ribs under optical microscope, Chun-Chieh and Cheng-Cheng say. So far authenticated DNA and red blood cells are not found in any dino fossils yet, and erythrocyte-like dark particles were identified as hematite afterwards by using confocal Raman microscopy. Two-dimensional distribution and tomography of the hematite particles and lacunae in the dino rib are also realized by utilizing transient absorption microscopy (TAM) and synchrotron transmission X-ray microscopy (TXM), respectively. “The tomography results obviously showed that the hematite particles are aggregated micro-sized hematite crystals,” Chun-Chieh Wang says.
“DNA’s half-life time is about 521 years reported by Australia palaeogeneticists,” Yao-Chang says. It is rare possibility to be remained for hundreds million years for the integrity of DNA molecule. Therefore, the protein primary structure of collagen extracted from fossil would be one of the crucial ways to unfold dino DNA code for revealing the genomic relation among extant species.