Dinosaurs Vs Mammals - Dinosaur Extinction
Homepage > Dinosaur Extinction - Dinosaurs vs Mammals
Had
the extinction of the dinosaurs not happened 65 million years ago, our
species would probably never existed. The extinction that happened during
the end of the Cretaceous Period was a major event that shaped the tree
of evolution, and it was during this pivot point that mammals would reign
as dominant vertebrates on land.
One of the puzzling pieces, however, is why mammals survived this major event while the dinosaurs went extinct.
According to Penn State researcher Russ Graham, the lifestyles of mammals gave them an advantage when the asteroid struck the area that is today’s Yucatan peninsula about 65 million years ago. In response to a “probing question” published on the university’s website, Graham opined that mammals that used burrows or lived in aquatic environments would have been shielded from the intense heat that briefly followed the impact. Once the heat was off, mammals could come back out and make the most of the remaining food resources. There may not have been enough food for dinosaurs, but the more generalized tastes of mammals allowed them to hang on.
Yet the Cretaceous mass extinction is not quite so clear cut. Much of what we know about the last days of the dinosaurs has come from North America, close to the site of impact, so how the pattern of extinction emerged elsewhere in the world is still poorly understood. And, contrary to popular perceptions, mammals did not escape the extinction event unscathed. Several groups of mammals most people have never heard of (like the triconodontids, spalacotheroids, dryolestids and multituberculates) perished right at or not long after the extinction event. Some groups of mammals did survive, but others were either wiped out or so reduced in diversity that, like the dinosaurs, they fell into extinction.
Mass extinctions are the greatest murder mysteries ever known. Figuring out why some forms went extinct and others survived is no easy task, and I doubt that even the mythical deductive powers of Sherlock Holmes could have resolved the puzzles facing paleontologists. The survival of some mammals is itself just one mystery embedded in a more perplexing question, and scientists are still busily collecting evidence from the scene of the crime.
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