Forgotten 17 Years, Bone Uncovers Giant Prehistoric Bird in 'Hobbit' Caves

An international group of researchers has made the first unequivocal discovery of fossilized red blood cells and collagen amino acids in the bones of a dinosaur dating back 115 million years. These findings were made in deposits in the Araripe Basin, Brazil.

The authors of the study, published in the Proceedings of the National Academy of Sciences of the United States, emphasized that this discovery fundamentally changes the understanding of preservation processes and molecular longevity over long periods of time.

The red blood cells belong to a theropod dinosaur species, Aratasaurus museonacionali, which is the only known representative of the extinct genus Aratasaurus. This animal could reach a length of up to three meters and weigh about 34 kilograms; its fossils date back to the Cretaceous period (115–110 million years).

The bones were found in the Romualdo Formation deposits in northwestern Brazil and are presented in a scientific paper published in 2020. Researchers determined that numerous red blood cells were preserved within the vascular channels of these bones.

Although previous studies suggested the possible presence of structures resembling red blood cells, the current research is the first to chemically prove the presence of molecules derived from hemoglobin inside the cells.

The samples contained preserved hemin—a component of hemoglobin responsible for oxygen transport, which, according to one of the authors, confirms the existence of traces of fossilized blood. Kleti Grise, director of the Centre for Organic and Isotopic Geochemistry at Curtin University in Australia, noted that the discovery of intact molecules derived from hemin in 115-year-old red blood cells is a historic finding.

The research team, which also included scientists from the Japan Agency for Marine-Earth Science and Technology, the National Museum of Brazil, and the Regional University of Cariri, as well as Johns Hopkins University, believes that such exceptional preservation occurred due to the rapid burial of the dinosaur in an environment with low oxygen content and high microorganism content immediately after its death.

Grise and her colleagues suggest that the red blood cells mineralized into hausmannite—a manganese oxide mineral—which likely served as a natural time capsule, helping to stabilize cellular structures and biomolecular components (including collagen amino acids) over such a long geological period.

The researcher stressed that this discovery not only expands the known registry of fossilized blood but also provides a direct molecular view into the physiology of long-extinct animals, allowing for a better understanding of them and their surrounding world. The results call into question established hypotheses regarding whether some biomolecules, such as hemoglobin, can survive for long periods. The authors concluded that this study redefines the ways in which molecular structures are preserved under long or hostile conditions, which may have implications for astrobiology and the search for ancient life in the universe.

Scientists recently announced the identification of a new species of dinosaur whose remains were discovered in 2001 in southern England. This fossil, named Paludohadros proudlovii, belongs to the group of iguanodontians—herbivorous dinosaurs that were widespread during the Cretaceous period, approximately between 145 and 66 million years ago.

The identification was conducted by paleontologist Ricardo Sacamonto, a researcher from the Paleontology Laboratory of the Faculty of Philosophy, Sciences and Letters of the University of São Paulo (FFCLRP/USP), who worked as part of a team led by Professor Max Langer.

The study, published on Tuesday (the 26th), details the new genus and new species of dinosaur based on remains found in the Smokejacks Brickworks area in southern England. These materials are housed at the Natural History Museum in London, where Sacamonto conducts his research.

During a re-evaluation of the specimen, the researcher discovered characteristic features that allowed it to be classified as a new species—Paludohadros proudlovii. According to Sacamonto, this was an herbivorous dinosaur that existed in the Lower Cretaceous period, over 100 million years ago, within the Barremian interval (approximately between 125.77 and 121.4 million years ago). Its fossils were found in the Weald Clay formation, a geological layer recording the ancient landscapes of southern England.

This finding is significant because it is the first iguanodontian—a bipedal herbivorous dinosaur—described specifically for this locality and geological layer. Although other dinosaurs of this group were previously known in the wider Weald Basin, they originated from older geological strata. Thus, the discovery expands the understanding of the diversity of these herbivores at the beginning of the Cretaceous period, notes Sacamonto.

Even as a juvenile specimen, Paludohadros proudlovii was a large animal. The researcher reported that the studied specimen weighed about 1.5 tons and was approximately four meters long, comparable to the size of a rhinoceros. Since it is a young individual, it is impossible to determine the maximum size this species could have reached; however, it is hypothesized that fully developed adults could reach lengths of six to eight meters and weigh twice as much as the analyzed specimen.

The species identification was made possible by analyzing specific anatomical features of the fossils, including jaw structures, limbs, pelvis, and legs. Among the observed features were tooth details, bony protrusions, and growths on various parts of the skeleton. Sacamonto emphasizes that the combination of these traits 'allowed the animal to be distinguished from other described iguanodontians.'

Paludohadros proudlovii was described by paleontologists as representing an 'early divergence,' as it belongs to an evolutionary group of dinosaurs that separated from other lineages at relatively early stages of evolutionary history. In the researchers' opinion, this study helps to understand how 'different groups of iguanodontians diversified throughout the Cretaceous period.'

The name Paludohadros proudlovii is related to the place of discovery. The specific designation proudlovii is a tribute to William Proudlove, the brickworks manager who worked at the quarry where the fossil was found. Proudlove died at the age of 35 shortly after the material was extracted.

This choice reflects the connection between the history of the specimen and the people involved in its discovery, while also highlighting the importance of paleontological collections. Sacamonto added that 'fossils extracted decades ago can continue to reveal new information with deeper study and comparison with other materials.'

The description of Paludohadros proudlovii is part of a broader study of iguanodontians preserved at the Natural History Museum in London. Sacamonto plans to dedicate the next four years of his doctoral dissertation to re-evaluating other specimens of this group held in the museum. He optimistically predicts that 'the chance of finding new species is quite high,' given the large amount of material yet to be studied. Some of these fossils may belong to the newly discovered species, while other specimens might reveal characteristics that help identify new species.

In addition to expanding knowledge about herbivorous dinosaurs inhabiting Great Britain, this research demonstrates how the reassessment of scientific collections can change the perception of the diversity of animals that inhabited Earth in the past. The fossil, discovered in 2001 but only now identified as belonging to a new species, proves that museum collections still hold important information about the evolution of life.

The research was funded by the Bepe Program (Scholarship for External Research Stays) of the São Paulo State Research Foundation (Fapesp). The article 'A new iguanodontian dinosaur from the Weald Clay Formation (Lower Cretaceous) of Smokejacks Brickworks, southern England' was published in the Journal of Systematic Palaeontology.