Post by Supersaurus on Nov 7, 2009 14:08:50 GMT -5
Just found this great article:
"Quickly, before you read the rest of this, round up the nearest four-year-old and ask how big the dinosaurs were.
(Pause while you talk to a four-year-old.)
Any self-respecting dinosaur maven, professional or preschool, will tell you of giant reptiles, some so large they may have waded through swamps so that the water would help support their weight. Think of the great sauropods--the four-legged, long-necked masters of the Jurassic Period--such as Apatosaurus (formerly called Brontosaurus) and its kin.
Now look at this:
(Illustration in Nature.)
A German team, writing in Nature, reports today that it's found Jurassic dinosaurs the size of farm animals. Some of them were still pretty big--twenty feet from nose to tail--but that's tiny compared to what you'll find in natural-history museums.
So why did the German team find such wimps of the Mesozoic? Right there in a quarry in northern Germany? They first thought they'd found dinosaur children, but it turned out dinosaur bones have the fossil equivalent of tree rings. These guys were grownups.
(Dinosaur models at Dinopark Munchenhagen in Germany.)
A more likely explanation: the dig site, 140 million years ago, may have been an island, and its dinosaur residents were "island dwarves." They were smaller than their mainland cousins, possibly for lack of predators, possibly because they were undernourished.
That's been seen before, but never in dinosaurs. (You may remember the "Hobbits" found in Indonesia in 2004. They were labeled as a newly-found species of early human, but they too may only be dwarves.)
There may be an evolution lesson here. The mini-dinosaurs, limited by the place where they lived, adapted to it. Or someone may come up with a competing theory to explain their size."
;D ;D ;D
"Quickly, before you read the rest of this, round up the nearest four-year-old and ask how big the dinosaurs were.
(Pause while you talk to a four-year-old.)
Any self-respecting dinosaur maven, professional or preschool, will tell you of giant reptiles, some so large they may have waded through swamps so that the water would help support their weight. Think of the great sauropods--the four-legged, long-necked masters of the Jurassic Period--such as Apatosaurus (formerly called Brontosaurus) and its kin.
Now look at this:
(Illustration in Nature.)
A German team, writing in Nature, reports today that it's found Jurassic dinosaurs the size of farm animals. Some of them were still pretty big--twenty feet from nose to tail--but that's tiny compared to what you'll find in natural-history museums.
So why did the German team find such wimps of the Mesozoic? Right there in a quarry in northern Germany? They first thought they'd found dinosaur children, but it turned out dinosaur bones have the fossil equivalent of tree rings. These guys were grownups.
(Dinosaur models at Dinopark Munchenhagen in Germany.)
A more likely explanation: the dig site, 140 million years ago, may have been an island, and its dinosaur residents were "island dwarves." They were smaller than their mainland cousins, possibly for lack of predators, possibly because they were undernourished.
That's been seen before, but never in dinosaurs. (You may remember the "Hobbits" found in Indonesia in 2004. They were labeled as a newly-found species of early human, but they too may only be dwarves.)
There may be an evolution lesson here. The mini-dinosaurs, limited by the place where they lived, adapted to it. Or someone may come up with a competing theory to explain their size."
;D ;D ;D
