Scientists have discovered fossils of dinosaur remnants of red blood cells

　　In a discovery that could provide new insight into dinosaur physiology, and may determine if certain species were warm-blooded or cold-blooded, a team of UK researchers has discovered the remnants of red blood cells and connective tissue in ancient fossils.
　　During the course of their work, experts from Imperial College London discovered tiny ovoid structures that had a denser inner-core, much like red blood cells, the British news outlet said. It also reported that the scientists found fibers with a banded structure, not unlike that in modern-day collagen in the ligaments and tendons of animals.
　　Soft tissues discovered in poorly-preserved fossils
　　While this not the first time that these types of soft tissues have been detected in dinosaur fossils, the previous reports came from unusually well-preserved specimen that suggested that they may have been contaminated in some way, study co-author Dr. Susannah Maidment told BBC News. In contrast, this study found soft tissues in poorly-preserved fossils.
　　In fact, Dr. Maidment said that these fossils had been lying around in the London Natural History Museum collections for more than a century, and described them as “scrappy, individual broken bones” from an unknown type of dinosaur. “If you’re finding soft tissues in these kinds of fossils, maybe this kind of preservation might be more common than we realized.”
　　Reports indicate that the structures appear to be genuine soft-tissue remains that have not been fossilized, and that chemical analysis of the suspected collagen protein(http://www.cusabio.com/catalog-13-1.html) and red blood cells was carried out with a mass spectrometer. That analysis revealed fragments of what appear to be the building blocks of proteins known as amino acids, and the chemical profile of the cells looked similar to those of an emu, a direct descendent of dinosaurs, the authors explained.
　　Analysis may determine which dinosaurs are related, warm-blooded
　　In vertebrates, creatures with smaller red blood cells have faster metabolic rates and tend to be warm blooded, and creatures with larger ones have slower metabolic rates and are typically cold blooded, Dr. Maidment told BBC News. While experts are not certain if this is true in dinosaurs, they may be able to find out if they can start finding red blood cells of various species.
　　Similarly, by studying the apparent collagen fibers, the research team may be able to learn more about the relationships between different dinosaur species. Using a technique known as collagen fingerprinting, which is based on the notion that the structure of an animal’s collage molecule is unique to that creature, they could determine which dinosaurs are related to each other.
　　“We still need to do more research to confirm what it is that we are imaging in these dinosaur bone fragments,” co-author Dr. Sergio Bertazzo added, “[but] if we can confirm that our initial observations are correct, then this could yield fresh insights into how these creatures once lived and evolved.”