Skip to comments.Aussie dinosaur bone takes bite out of theory of continental drift
Posted on 06/13/2008 7:42:26 AM PDT by BGHater
A dinosaur bone discovered in Australia has defied prevailing wisdom about how the world's continents separated from a super-continent millions of years ago, a new study published on Tuesday said.
The 19-centimetre (eight-inch) bone was found in southeastern Australia but it comes from a very close cousin to Megaraptor, a flesh-ripping monster that lorded over swathes of South American some 90 million years ago.
The extraordinary similarity between the two giant theropods adds weight to a dissident view about the breakup of a super-continent, known as Gondwana, that formed the continents of the southern hemisphere, the authors say.
Gondwana broke up during the Cretaceous period to form South America, Africa, Antarctica and Australia.
The standard theory is that the first continents to go were South America and Africa, which pulled away from Gondwana around 120 million years ago.
Australia remained attached to Antarctica before the two entities drifted apart around 80 million years ago, according to this theory. Australia began an insular existence that incubated flora and fauna which remain unique to this day.
The forearm bone, found near Cape Otway in the state of Victoria, is the first link ever found between a non-flying therapod -- or two-footed dinosaur -- in Australia and another component of Gondwana.
The investigators, led by Nathan Smith of the University of Chicago, say the two dinosaurs are so similar the two land masses of South America and Australia could not have been separated for so many millions of years beforehand.
If that had been the case, evolutionary pressures would have pushed the dinos in different directions as they adapted to their changing environments.
They speculate that land bridges must have persisted between southern South America and the Western Antarctic Archipelago "until at least the Late Eocene," a period that began some 40 million years ago.
The study is published in the Proceedings of the Royal Society B, a journal of Britain's de-facto academy of sciences.
That’s truly interesting ... thanks for posting!
Is an eight inch fossil sufficient evidence to conclude that the continents moved differently than previously thought? Or evidence that two species in different places were remarkably similar?
Either way, it seems like a lot to conclude from such a small piece of evidence.
“They had a fancy name for it but I don’t recall.”
I'm curious why the fossil can't be seen as evidence of a convergent trait. Instead they want to alter the existing theory on continental drift. Seems drastic.
“Either way, it seems like a lot to conclude from such a small piece of evidence.”
BINGO. Continental drift, evolution, ozone hole, global warming, you name it. Examine the assumptions, find the agenda.
We have a winner!
Actually its better not to pay much attention to the media description of these discoveries. The actual paper by the discoverers is usually very different.
This makes no sense since dinosaurs went extinct 65 million years ago.
Tell that to the Crocodile.
Crocodile are NOT dinosaurs.
Crocodiles are NOT dinosaurs.
But they are so cute. Especially when they tear into a zebra. They ought to be a dinosaur.
One question I have always had concerning continental drift:
How do we know that the plates have been moving at the same rates over this entire period of time? I believe they say the plates move about an inch a year or so currently. How do we know they didn’t move for example at a mile per year at some time in the past?
I'd expect there would be substantial geologic evidence if that happened. The volcanic activity along the Pacific rim is where the plates are being pulled apart, and exposing the mantle. The volcanic activity would be immense. On the opposite side, they're being pushed together and pusing up mountains. I'd think plate drift of that magnitude would have consequences that would leave some pretty impressive evidence.
Another excuse for me to post this!
Now, if I wanted to be one of those ponderous scientific people, and "let on" to prove what had occurred in the remote past by what had occurred in a given time in the recent past, or what will occur in the far future by what has occurred in late years, what an opportunity is here! Geology never had such a chance, nor such exact data to argue from! Nor "development of species," either! Glacial epochs are great things, but they are vague--vague. Please observe:--
In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oölitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing rod. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three quarters long, and Cairo and New Orleans will have joined their streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.
Mark Twain, Life on the Mississippi, Chapter XVII (Pg 209)
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