What ultimately wiped out the dinosaurs ? Image Credit: CC BY-SA 2.5 Gerhard Boeggemann
A new study has suggested that the dinosaurs had already been dying out long before the asteroid hit.
The impact, which occurred 66 million years ago, has long been attributed with the extinction of the dinosaurs, yet there is strong evidence to suggest that these prosperous reptiles may have already been on the decline and that the apocalyptic asteroid strike had simply tipped them over the edge.
By conducting a statistical analysis of fossils from three of the largest dinosaur family trees, a team of scientists led by palaeontologist Manabu Sakamoto of Reading University have determined that the dinosaurs may have even been on their way out for tens of millions of years beforehand.
"While the asteroid impact is still the prime candidate for the dinosaurs' final disappearance, it is clear that they were already past their prime in an evolutionary sense," said Dr Sakamoto.
"While a sudden apocalypse may have been the final nail in the coffin, something else had already been preventing dinosaurs from evolving new species as fast as old species were dying out."
This gradual decline, coupled with the devastating effects of the asteroid strike, would have left plenty of room for mammals to flourish both before and after the dinosaurs went extinct.
New Study, I always thought this theory had been floating around for a couple of years. The study looks like just a duplication of what Robert Bakker published in the early 1980's - outlined for us regular folks in his book "The Dinosaur Heresies" in 1986 link. Bakker blamed disease primarily, IIRC. His study showed dramatic drops in the variations among different members of the same genus. The disappearance of large numbers of species indicates problems, even if those species had their niches filled by other members of their genus. Fewer kinds of stegosaurs or ceratopsians, for example, in ot... [More]
But dinosaurs didn't go extinct. You can see them everywhere today as birds which evolved from feathered dinosaurs. I'll remember that next time I see a T-rex land in my backyard.
I'm sorry but there is no possible way that scales evolved into feathers. Research the structure of a feather and the scales from lizards and dinosaur fossils. I don't see how that claim can be made of scales to feathers. There has to be another reason for feathers.
I'm sorry but there is no possible way that scales evolved into feathers. Research the structure of a feather and the scales from lizards and dinosaur fossils. I don't see how that claim can be made of scales to feathers. There has to be another reason for feathers. You appear not to know of the multiple feathered dinosaur finds. Turn out a lot of different kinds had feathers of some sort. Harte
So this is a "plebeian" version of Bakker's theory from long ago? Don't know. I'll let you know when I read this guy's book, if he writes one. But AFAIK Bakker was the first to show that there was a decline well before the K-T event. I'd guess other Paleontologists have shown things along similar lines in the 30 years since Bakker's book. I saw the paperback was 97 cents. It's a damn good dinosaur book. Harte
The article isn't clear, but a decline in species without a decline in populations might simply indicate that the remaining species were optimally adapted to their environment. Competing species, being less able to exploit the available resources, perished. After 160 million years of evolving, maybe dinosaurs were asymptotically approaching perfection.
Over specialization is an old idea for their extinction. It certainly isn't a bad one, as the possibility for a homogenous population being unable to adapt quickly to changes in environment from competition or climate or changing ecosystems is a real possibility. Grasslands started to appear around the same time that sauropods started to diminish, for example.
Makes sense, given their lumbering size, although some did manage to evolve into more 'doable size' birds. And other reptiles like the crocodile survived the comet too. :-)
I read about this and thought..how long? The dinosaurs were already in decline 50 million years before the asteroid strike that finally wiped them out, a study suggests. http://www.bbc.co.uk...onment-36073592 50 millions years? that's some slow decline. Where does that leave us, I can not even contemplate humans being here for that long, let along declining over that period of time.
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