Category Environment/Geology

Scientists have directly measured the air that was breathed by Earth’s first animals for the first time

The discovery of an atmospheric time capsule has allowed scientists to directly measure the air breathed by the first animals. A team of international researchers, including geologists from the University of Aberdeen, made the discovery while analysing samples of halite ie rock salt – dated 815 million years old. The halite was found to contain traces of trapped atmospheric gas, from which measurements of oxygen were taken. The analysis found that the percentage of oxygen present in the atmosphere 815 million years ago was enough for animals to flourish. Some studies have suggested that the required level of oxygen would only have been present much later in the Earth’s history.

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Artistic rendering of the early proto turtle Eunotosaurus (foreground) burrowing into the banks of a dried up pond to escape the harsh arid environment present 260 million years ago in South Africa. Meanwhile, a herd of Bradysaurus (background) congregates around the remaining muddy water. Credit: Andrey Atuchin

A new study by an international group of paleontologists suggests that the broad ribbed proto shell on the earliest partially shelled fossil turtles was initially an adaptation, for burrowing underground, not for protection. “Why the turtle shell evolved is a very Dr. Seuss-like question and the answer seems pretty obvious – it was for protection,” said Dr. Lyson...

The preservation of Cretaceous mollusk fossils from Seymour Island is excellent, with shells preserving original mother-of-pearl material as in these two specimens of Eselaevitrigonia regina. Credit: Sierra V. Petersen

A new reconstruction of Antarctic ocean temperatures around the time the dinosaurs disappeared 66 million years ago supports the idea that one of the planet’s biggest mass extinctions was due to the combined effects of volcanic eruptions and an asteroid impact. 2 University of Michigan researchers and a Florida colleague found 2 abrupt warming spikes in ocean temperatures that coincide with two previously documented extinction pulses near the end of the Cretaceous Period...

This diagram depicts the way a mid-infrared laser (red cylinder, left) can send a beam through the atmosphere that generates filaments of ionized air molecules (multicolored beam, center, shown with magnified view). These filaments, which can be kilometers long, help to keep the beam concentrated enough to generate mid-infrared light in air (blue cloud, right) that can reveal detailed chemical composition through spectral analysis (chart at right) of the light picked up by a mid-infrared detector (bottom). Credit: Diagram courtesy of the researchers

Researchers have found a new way of using mid-infrared lasers to turn regions of molecules in the open air into glowing filaments of electrically charged gas, or plasma...