Dinosaurs were flourishing in Europe right before their rapid demise, according to a new study. This would help confirm that dinosaurs the world over were wiped out by an asteroid’s impact 66 million years ago - a theory sometimes questioned due to lack of non-North American fossil evidence.
“The European fossil record, just as that from North America, suggests a rather sudden event that swept quasi-instantaneously through ecosystems that otherwise were doing quite well,” team leader Zoltan Csiki-Sava, of the University of Bucharest, said. “We do not see a pattern of dwindling diversity that finally peaked in the extinction event itself, but instead one of rich and diverse local faunas distributed across the European islands, faunas that were abruptly decimated without any prior warning.”
While most in the science community agree that a comet is what ultimately killed off the dinosaurs, a debate continues over how well they were doing when the 6-mile wide rock hit the Yucatan Penninsula at the end of the Cretaceous period. “The asteroid didn't hit a static, idyllic 'lost world' of the dinosaurs,” Stephen Brusatte, an author of the report, told FoxNews.com. “It hit a planet that was experiencing intense volcanism and temperature and sea level change. So there has been a debate about whether some of these things were gradually weakening the dinosaurs, and then the asteroid was more of a final blow.” All of the evidence supporting a rapid widespread dinosaur die-off up until now has been collected in North America. However, the past 20 years has seen a groundswell in European research and the continent has offered some of the best late-Cretaceous fossil samples to date. The Pyrenees mountain range in France and Spain, for example, is one of the best areas in the world for finding late-Cretaceous fossils.
“Data collection concerning end-Cretaceous dinosaurs happened to start at about the same time in both Europe and North America – around the middle of the 19th century,” Csiki-Sava said. “It is only by chance (a combination between mainly better rock availability and more human effort poured into this line of research) that the North American fossil record grew more rapidly and soon become the best one in the world for that particular time period. As such, it captured attention and was used as a template to understand end-Cretaceous extinction. The data was harder to gather in other continents, including Europe, and the resolution of the European fossil record is still far from that coming from North America. But its growth is spectacular (we know probably twice as much about late Cretaceous fossil vertebrates from Europe then we knew like 20 years ago), and that is due to the activity of a large number of mainly young researchers working all across Europe.”
The new study is a combination of late-cretaceous fossil research - not just of dinosaurs, but of other land-living vertebrates as well - culled from all across Europe. “Although dinosaurs are an important part of this picture, they only tell part of the story, because there were both losers and winners (survivors) of the end-Cretaceous extinction event,” Csiki-Sava told FoxNews.com. “So we [chose] to look at the complete picture, to gain a better understanding of the events that took place 66 million years ago and wiped [out] – among other organisms – the dinosaurs.”
The researchers surveyed how the creatures were changing right up to point of the asteroid’s impact. It painted a picture of a species that was thriving, far from the brink of extinction “Our survey showed that dinosaurs were quite common in Europe during the final few million years before the asteroid hit,” Brusatte said, “and -at least in Spain, the one place that preserves good fossils right bang at the end of the Cretaceous - there were numerous types of dinosaurs thriving during the last few hundred thousand years before the asteroid hit. That is about as good of resolution as we can get with the fossil record.”
The theory that a comet killed the dinosaurs first gathered worldwide attention when Walter Alvarez posited it in 1980, pointing to an increase in iridium levels (the substance asteroids are made of) in the Earth approximately 66 million years ago. At first, the theory was widely contested by the science community. “For a few years it was very controversial,” Brusatte says, “but then later in the 80’s a crater was found in Mexico (the Chicxulub Crater) that is dated to exactly 66 million years ago, right when the dinosaurs died. There is also all other kinds of evidence that an asteroid hit- but the crater is the smoking gun. So we know for an absolute fact that a big asteroid, about 6 miles wide, hit Mexico at the end of the Cretaceous.”
Various models have suggested the prehistoric creatures were killed off by heat from the impact, whose accompanying blast would have released more TNT energy than a billion times that of an atom bomb. Other theories say it was a global cooling brought about by dust kicked up in the blast. “Both effects would have lasted something at the order of at most hundred years, far below our capabilities to detect timescale of events,” Csiki-Sava said. “So the unfortunate answer (for the public, at least; I think most scientists can live with it) is that we will probably never know whether it was the heat or the cold, of a combination of these, or an even more complex combination. All we can see is that many of these species were wiped out rapidly – but you have to consider that this is geologically speaking ‘rapidly’, which can mean anything at the order of hundreds of thousands to about 1 million of years, as it is impossible to have a better accuracy time-wise.”