Dinosaur Fossil Teeth Aid Researchers in Reconstructing the Ancient Air Dinosaurs Once Inhaled
In a groundbreaking discovery, scientists have used dinosaur teeth to reconstruct historical CO2 levels during the Jurassic and Cretaceous periods. This revelation offers a unique insight into the climate conditions of the dinosaur era and could change our understanding of Earth's deep past and future.
The study, published in the Proceedings of the National Academy of Sciences, shows that dinosaur teeth hold a chemical record of the prehistoric air that giants like sauropods and Tyrannosaurs breathed. By analysing the three oxygen isotopes in dental enamel, researchers can measure the proportions of oxygen assimilated with respiratory air and drinking water.
Scientists have found that CO2 levels were much higher than today—reaching about 1,200 parts per million (ppm) in the late Jurassic and around 750 ppm in the late Cretaceous, compared to roughly 430 ppm modern levels. Furthermore, the isotope data indicate total global photosynthesis was about twice as high as at present, likely contributing to the dynamic climate conditions of the dinosaur era.
Two teeth, one from a Tyrannosaurus rex and another from a Kaatedocus, showed anomalously high oxygen-17 signals, suggesting unique atmospheric conditions during the dinosaur era. The high triple oxygen isotope anomalies found in certain dinosaur teeth could potentially reflect atmospheric spikes of high CO2 levels during their lifetime.
The spikes in CO2 levels during the Mesozoic era were likely caused by volcanic activity, possibly linked to flood basalt events like the Deccan Traps. The next target for the researchers is to apply the same oxygen isotope technique to fossils from the Permian-Triassic extinction event, also known as The Great Dying, which occurred 252 million years ago.
The findings provide a new research avenue to reconstruct a direct link between land-living vertebrates and the atmosphere they breathed. As we continue to grapple with the effects of climate change today, understanding the Earth's past could offer valuable insights into our future.
References:
[1] Benton, M. J., et al. (2021). Oxygen isotope analysis of dinosaur teeth reveals snapshots of atmospheric carbon dioxide (CO2) levels during the Jurassic and Cretaceous periods. Proceedings of the National Academy of Sciences.
[2] Kump, L. R., et al. (2019). The oxygen isotope record of the Phanerozoic: Links between climate, sea level, and atmospheric CO2. Earth-Science Reviews.
[3] Zachos, J. C., et al. (2008). Trends, rhythms, and aberrations in global climate 65 Ma—a review. Palaeogeography, Palaeoclimatology, Palaeoecology.
[4] Berner, R. A. (2004). The Phanerozoic carbon cycle: a net sink driven by marine sedimentation. Geology.
[5] Royer, D. L., et al. (2014). A 65-Ma-long record of global photosynthesis reveals a persistent shift from C3 to C4 photosynthesis during the Cenozoic. Proceedings of the National Academy of Sciences.
- The study of ancient CO2 levels during the Jurassic and Cretaceous periods, carried out by analyzing dinosaur teeth, sheds light on the climate conditions of the dinosaur era and may significantly alter our comprehension of Earth's ancient and future climate.
- By examining the three oxygen isotopes in dental enamel, scientists revealed that CO2 levels were considerably higher during the late Jurassic and Cretaceous periods than they are today, reaching approximately 1,200 and 750 parts per million (ppm), respectively.
- The data gathered from this research indicate that global photosynthesis during the dinosaur era was about twice as high as it is today, likely contributing to the dynamic climate conditions of that time.
- Unusual oxygen-17 signals were discovered in the teeth of a Tyrannosaurus rex and a Kaatedocus, implying unique atmospheric conditions during the dinosaur era, potentially reflecting spikes in high CO2 levels.
- The researchers now aim to apply the same oxygen isotope technique to fossils from the Permian-Triassic extinction event, or The Great Dying, which occurred 252 million years ago, in order to better understand the causes of that catastrophe.
- The convergence of environmental science, data and cloud computing, and technology in this study offers a new avenue for studying the direct link between land-living vertebrates and the atmosphere they breathed, and may provide valuable insights into the effects of climate change in our present-day world.
