The reign of the dinosaurs ended in spring

The asteroid that killed nearly all dinosaurs struck Earth during springtime.  An international team of scientists from the Vrije Universiteit (VU) Amsterdam (The Netherlands), Uppsala University (Sweden), Vrije Universiteit Brussel (Belgium) and the ESRF, the European Synchrotron (France), have determined when the meteorite crashed onto the Earth, after analysing the remains of fish that died just after the impact. Their results are published in the journal Nature today.

Around 66 million years ago, the Chicxulub meteorite crashed into the Earth, in what today is the Yucatán peninsula in Mexico, marking the demise of dinosaurs and end of the Cretaceous period. This mass extinction still puzzles scientists today, as it was one of the most selective in the history of life: all non-avian dinosaurs, pterosaurs, ammonites, and most marine reptiles disappeared, whilst mammals, birds, crocodiles, and turtles survived.

A team of scientists from the Vrije Universiteit, Uppsala University, and the ESRF have now shed light on the circumstances surrounding the diverse extinction across the different groups. The answers came from the bones of fish that died moments after the meteorite struck.

Read more on the ESRF website

Image: Melanie During points to a section of a Paddlefish dentary showing high bone cell density (i.e. summer)

Credit: Melanie During

Analysing asteroid Ryugu samples

The asteroid Ryugu samples brought back by JAXA’s asteroid explorer “Hayabusa2” in December 2020 are analyzed by six initial analysis teams for one year from June 2021. Among the initial analysis teams, the “Stone Material Analysis Team” and the “Organic Macromolecule Analysis Team” conducts their analysis at the Photon Factory, KEK.

It is thought that asteroids such as Ryugu may have brought water and organic matter to the Earth in the past. By integrating the results of each team’s analysis, we will be closer to solving the great mystery of how life came to be on the Earth.

Read more on the HAYABUSA2-IMSS website

Image : Primordial solar system.