An article published in the journal “Nature Communications” describes a research based on the analysis of more than 6,000 fossils of Antarctic marine organisms concluding that the mass extinction occurred at the end of the Cretaceous period that wiped out the dinosaurs was as deadly in the polar regions. This contradicts the idea that in far south regions of the world there would be less danger during that event.

This research went on for about six years and is based on the identification of more than 6,000 marine fossils with an age between 69 and 65 million years, meaning that they’re from the late Cretaceous. They were excavated on Seymour Island in the Antarctic Peninsula during a research with the participation of scientists from the University of Leeds and the British Antarctic Survey.

The result is one of the largest collections in the world of marine fossils of that age. It includes a large variety of species belonging to different phyla. The grouping of fossil by age shows a reduction of 65-70% in the number of species that lived in Antarctica 66 million years ago, coinciding exactly with the great mass extinction that wiped out the dinosaurs.

According to James Witts, the article’s main author, this is the strongest evidence derived from the fossil record that that mass extinction was the catastrophic effect of an asteroid impact and not of a slow decline due to other causes. It’s also the first study that shows that that extinction was severe even in the polar regions.

So far, paleontologists tended to think that the organisms that lived in polar regions were far away enough from the cause of the mass extinction not be influenced by it as much as others. An argument concerned the fact that they were less sensitive to climate change associated with an asteroid impact because for example they were already accustomed to long periods of darkness.

Reasons to discuss the causes of that extinction are also due to the fact that some groups of dinosaurs appear to have already been in decline well before 66 million years ago. According to some paleontologists, the problem is fossil record limits and in the case of this research on marine organisms instead there’s an abundance that leaves no room for doubt.

According to a research published last year, the huge volcanic activity in the Deccan Traps was a consequence of an asteroid impact and inflicted another blow to the world’s ecosystems only after that. The results of the research on the extinction of Antarctic organisms doesn’t contradict that theory so both of them could tell different parts of that story.