Category Environment/Geology

NASA/JPL-Caltech/STScI/CXC/SAO Oceanic sediment contains an iron isotope that ancient bacteria accumulated 2.2 million years ago when debris rained on Earth from a supernova explosion. Shown are the remnants of a much younger supernova remnant, Cassiopeia A, shown in a composite image from three NASA observatories.

A team from Germany and Austria has found possible evidence of iron from a supernova in sediment cores taken from the floor of the Pacific Ocean. The study began when team members came across information regarding magnetotactic bacteria during internet searches. It is a type of bacteria that lives in ocean sediments and absorbs tiny amounts of iron. As sediment builds, the bacteria die leaving behind bits of iron in the layers of sediment...

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...