[kellyhound]

Researchers have analysed the oxygen isotope ratios in fossilised dinosaur teeth, specifically the tooth enamel.

The tooth has preserved traces of the ancient atmosphere. The researchers studied these isotopes to understand atmospheric CO2 levels during the Mesozoic era, when dinosaurs roamed the Earth.

The CO2 levels were much higher during that time, with concentrations reaching up to 1,200 parts per million in the late Jurassic and 750 parts per million in the late Cretaceous.

To understand it better, today's atmospheric CO2 levels are around 430 parts per million.

The volcanic activity apparently played a significant role in shaping the prehistoric atmosphere. According to the researchers, some dinosaur teeth showed signs of high CO2 levels likely caused by large flood basalt eruption events.

"Our findings provide a new research avenue to reconstruct a direct link between land-living vertebrates and the atmosphere they breathed," palaeontologist and geochemist Thomas Tutken of the Institute of Geosciences at Johannes Gutenberg Universitat, Mainz in Germany, told.

"Even after up to 150 million years, isotopic traces of the oxygen molecules of the Mesozoic atmosphere that the dinosaur inhaled are still preserved in fossil tooth enamel and can tell us something about the ancient atmosphere composition and global photosynthetic biomass production."

Now, the team plans to apply this method to other geological periods, including the Permian-Triassic extinction event, to understand the Earth's climate history better.

This innovative approach has shed new light on the prehistoric atmosphere and has the potential to revolutionise our understanding of Earth's climate history.

"Overall, triple oxygen isotope analysis of fossil teeth of terrestrial amniotes can provide insights into past atmospheric greenhouse gas content and global primary productivity," the researchers wrote in the study.

[Mr.NoCredit]

And I honestly thought that there was a whole lot more oxygen back then and less carbon dioxide.

Lizards were ultra huge back then and only needed to walk on their hind legs.

[kellyhound]

the majority of dino's ate a variety of vegetation, but mostly ferns, cycads, conifers, ginkgoes, tree leaves and later in the era, flowering plants.

These flowering plants began to evolve and diversify rapidly, gradually replacing other plant groups due to higher co2 levels which also caused to evolve and growth of these angiosperms like most trees and cycads, conifers and ginkgo trees (gymnosperms) so animals grew taller also to reach for their food.

So predators grew also due to the growth of their prey. That's probably also a reason why they grew bigger being less vulnerable to predators and their babies grew too so they needed bigger bodies.

Scientist think that around 250 million years ago almost all marine species and 70% of terrestrial vertebrate species died, primarily caused by massive volcanic eruptions in Siberia causing very high levels of carbon dioxide into the atmosphere, leading to significant global warming and ocean acidification.

Most carbon dioxide gets absorbed by water (oceans) so less oxygen levels making it harder or impossible to breath for animals that live in the water. That also led to a decrease in seawater pH making it harder to form shells and skeletons.

Then roughly 50 million years later the earth's landmass began to break up due most likely to vulcanic eruptions etc. forming several new continents.

This also caused a large release of greenhouse gases, leading to global warming and drastic changes in the planet's ecosystems leading to 80% of all species to extinct.

However this created a vacuum in ecological niches, particularly on land, where dinosaurs were able to thrive. Dinosaurs, already present during the Triassic period, were able to diversify and expand their populations during the Jurassic period.

Then around 130 million years later, around 66 million years ago, an, around 6 miles wide asteroid or comet hit the Yucatan peninsula causing massive wildfires, huge tsunami and a massive aerial debris blocking the sunlight, causing acid rain and winter and causing plankton to die. This event led to the demise of about 75% of all plant and animal species on Earth.

Other groups, like mammals and birds, experienced a remarkable adaptive radiation. The extinction also triggered a shift in dominance within ecosystems, with mammals taking over from the dinosaurs as the dominant terrestrial vertebrates.

Mammals, particularly small, insectivorous ones, underwent rapid evolution and diversification, leading to the emergence of various modern mammal groups like bats, whales, and primates.

Marine ecosystems experienced a period of instability, with plankton recovering relatively quickly, but full biodiversity recovery took millions of years.

Although the asteroid theory has met with skepticism among some paleontologists, with some agitating for terrestrial factors as the cause of the extinction and others claiming that the amount of iridium dispersed by an impact was caused by a smaller object, such as a comet.

A huge outpouring of lava, known as the Deccan Traps, occurred in India at the end of the Cretaceous.

Some paleontologists believe that the carbon dioxide that accompanied these flows created a global greenhouse effect that greatly warmed the planet.

Others note that tectonic plate movements caused a major rearrangement of the world’s landmasses, particularly during the latter part of the Cretaceous.

The climatic changes resulting from such continental drift could have caused a gradual deterioration of habitats favourable to the dinosaurs and other animal groups that suffered extinction.

[Mr.NoCredit]

Dinosaurs were always a favorite wonder of mine. The first Jurassic Park movie was amazing especially for the cgi back then. It brought them back to life if even just for the two hours of movie.

Cool post.

[IvorySmith]

Originally Posted by kellyhound ↗

Scientist think that around 250 million years ago almost all marine species and 70% of terrestrial vertebrate species died, primarily caused by massive volcanic eruptions in Siberia causing very high levels of carbon dioxide into the atmosphere, leading to significant global warming and ocean acidification.

Good try, scientologists. We all know it was a result of that crazy liberal Miss Frizzle driving her Magic School Bus around wherever and whenever she wanted while the rest of us were locked down during covid.