In addition, this sedimentary burial action was taking place along vast environmental differences from north to south along the western basin, hence greater diversity in the fossils.īut there is another crucial factor: luck. 'The tectonic setting involving active arc volcanism, as well as intraplate volcanism, produced voluminous and widespread volcanic sedimentary deposits, primarily in the form of ash fall deposits, that we were able to apply the highest precision dating techniques currently available to start to unravel questions like this,' Roberts said. The answer, he said, is that the time was right for these fossils to be preserved due to widespread volcanic activity, which produced huge amounts of sediment. 'The real question is why are there so many dinosaurs and other vertebrate fossils preserved across the part of Western North America in rocks spanning such a short duration?' Roberts told Newsweek. Not necessarily, according to Eric Roberts, head of earth and environmental science at James Cook University in Australia and author of the aforementioned study.

So what is it about North America that makes it so abundant in fossils? Is it that this region was particularly habitable for dinosaurs, making it a global hotspot for diversification? According to a study on fossil preservation published Monday, fossils preserved in North America's Western Interior Basin record an 'exceptional peak' in the diversification of dinosaur fossils towards the end of the Cretaceous period.

Western North America, in particular, has been one of the greatest sources of dinosaur fossils in the world. Some of the most famous dinosaurs ever are thought to have lived in North America, including Tyrannosaurus. A stock illustration depicts a T-rex walking along the ancient Earth.

Goldilocks dinosaurs