1.媒体来源:
纽约时报
2.记者署名:
Katherine Kornei
3.完整新闻标题:
Long Limbs Helped Propel T. Rex Up the Dinosaur Food Chain
4.完整新闻内文:
Surviving in the Cretaceous wasn’t a sprint, it was a marathon. And
Tyrannosaurus rex was built to amble for hours, new research reveals. That
attribute might have helped propel the carnivore to the top of the food
chain, researchers suggest.
A study published earlier this month in PLOS One showed that some dinosaurs
were particularly efficient walkers because of their long hind limbs. Thanks
to their lanky legs, T. rex didn’t need to eat as much as its brethren, and
could therefore get away with hunting less frequently, the team concluded.
To understand the biomechanics of long-extinct animals, scientists rely on
fossilized bones and footprints. These records reveal information about a
creature’s bone and muscle structure and its stride, all of which affect its
ability to run. But identifying who is fleet of foot solely from imprints or
a pile of bones is challenging.
In 1976, Robert McNeill Alexander, a British zoologist, proposed that a
dinosaur’s maximum running speed depended on its stride length and hip
height. But that idea has been revised over time.
“Once you get to big animals, limb length doesn’t really dictate speed,”
said John Hutchinson, a biologist at the Royal Veterinary College in London
who was not involved in the research.
In recent years, scientists have realized that long legs will only get you so
far — body mass also plays a role. Elephants tower above thoroughbreds, but
there’s a reason the Kentucky Derby is run with horses.
To more accurately estimate dinosaur running speeds, Dr. Dececchi and his
colleagues amassed measurements of hind limbs and published body mass
estimates for 34 dinosaur specimens. For each of the specimens — ranging
from a tiny Archaeopteryx, a birdlike creature weighing half a pound, to a
20,000-pound T. rex — Dr. Dececchi and his collaborators compared
calculations of running speed.
The researchers determined that dinosaurs weighing less than a few hundred
pounds were actually faster according to the calculations that used their
body mass compared with the calculations that didn’t. In other words,
smaller dinosaurs weren’t slowed by their heft.
But the situation changed for animals larger than about 2,000 pounds — those
dinosaurs moved considerably slower, according to the equations that included
their mass compared with those that just included stride length and hip
height. For behemoths like Tyrannosaurus, that difference was significant: 18
miles per hour versus 45 miles per hour.
That schism left Dr. Dececchi and his colleagues wondering about the
evolutionary advantage of lanky limbs for a massive dinosaur. “Their legs
are longer than would help them for speed,” Dr. Dececchi said. Maybe those
limbs allowed the animals to amble more efficiently, the team hypothesized.
Dinosaurs like Tyrannosaurus walked about 10 miles per day, previous research
has suggested.
Dr. Dececchi and his collaborators analyzed groups of dinosaurs with very
similar masses but different leg lengths. For each animal, they estimated how
much energy it would expend to move at a slow walk. They found that
Tyrannosaurus used between 1 and 35 percent less energy than other related
dinosaurs.
“That potentially gave them a big advantage,” said Eric Snively, a
biologist at Oklahoma State University who was not involved in the research.
“The amount of energy you use in a day will dictate how much food you have
to eat.”
A Tyrannosaurus could get away with eating several hundred fewer pounds of
meat each year than its brethren, Dr. Dececchi and his colleagues calculated.
(That’s about one Ornithomimus, a beaked dinosaur that resembled a large
ostrich.) Because the carnivores typically hunted in packs, that savings
added up to tons less meat that needed to be hunted. Less frequent hunting no
doubt helped preserve the animals’ health.
“Every hunt runs a risk of injury,” Dr. Dececchi said. Staving off bodily
harm might have helped ensure the evolutionary success of Tyrannosaurus, he
said.
“It may have been one of the traits that allowed them to become so
successful.”
完整新闻连结 (或短网址):
https://www.nytimes.com/2020/05/23/science/tyrannosaurus-rex-legs.html
6.备注:
最近的期刊发表上
发现暴龙的四肢躯干 应该是用来长期慢跑而非电视演的冲刺
但是这反而是个优势
其他恐龙虽然可能跑得比较快 但是基本上不擅长长跑
(题外话 人类是少数可以长跑的动物之一)
而暴龙可以让猎物"累瘫" 再去捕食
也间接说明为什么 很少有暴龙被三角龙弄伤的证据
因为三角龙以为他跑的掉 就不正面硬肛了
然后就被暴龙追到没力QQ
不过台湾好像很少人喜欢恐龙QQ