Dinosaurs existed for 165 million years.

恐龙存在了1.65亿年。

The animals' evolutionary success was partly due to their fast growth rate.

这些动物的进化成功在一定程度上要归功于它们的快速生长。

A new study finds that this pattern of fast growth appeared in the earliest dinosaurs.

一项新的研究发现，这种快速生长的模式出现在最早期的恐龙身上。

The researchers examined microscopic details in dinosaur bone fossils from Argentina.

研究人员检查了来自阿根廷的恐龙骨骼化石的微观细节。

The details showed that the earliest dinosaurs had growth rates similar to animals found today like mammals and birds.

这些细节表明，最早的恐龙的生长速度与今天发现的哺乳动物和鸟类等动物相似。

Scientist Kristi Curry Rogers of Macalester College in Minnesota studies fossils.

明尼苏达州马卡莱斯特学院的克里斯蒂·库里·罗杰斯是研究化石的科学家。

She is the lead writer of the research recently released in the publication PLOS ONE.

她是最近发表在《公共科学图书馆·综合》杂志上的这项研究的主编。

She said, "Growing quickly allows organisms to escape the risky business of being small for a long part of their life history."

她说：“快速生长使生物体能够在其生命历史的很长一段时间里逃脱小体型的风险。

And she added that it also allows them to reproduce more throughout their life.

她补充说：“这也让它们在一生可以中繁殖更多的后代。”

That means each following generation will be more successful.

这意味着接下来的每一代后代都将更加成功。

The researchers examined patterns fossilized within the bones of dinosaurs and some of their relatives.

研究人员检查了恐龙及其近亲骨骼化石中的图案。

The dinosaurs they looked at lived in northwestern Argentina between 231 and 229 million years ago.

他们研究的恐龙生活在2.31亿至2.29亿年前的阿根廷西北部。

Curry Rogers said cellular and chemical details in the fossils all show relative speed of growth.

库里·罗杰斯说，化石中的细胞和化学细节都显示出相对增长的速度。

She added that the soft parts of the animal are no longer present, but the hard parts like the bones left a record of spaces where the soft parts once were.

她补充说，动物的柔软部分不再存在，但骨骼等硬部分在柔软部分曾经存在的空间留下了记录。

She said, "This allows us to reconstruct and compare growth patterns among animals."

她说：“这使我们能够重建和比较动物的生长模式。

The researchers studied five early dinosaurs.

研究人员研究了五只早期恐龙。

They all walked on two feet, were quick on their feet, had clawed hands that could hold objects and had sharp teeth.

他们都是用两只脚走路，脚步敏捷，有能握住物体的爪子，还有锋利的牙齿。

Three were meat-eaters and the ancestors of large meat-eaters like T. Rex and Giganotosaurus.

其中三种是肉食动物，也是大型肉食动物，比如特雷克斯龙和巨齿龙的祖先。

The dinosaurs included Herrerasaurus and Sanjuansaurus which were around 3-4.5 meters long.

这些恐龙包括约3-4.5米长的黑龙（Herrerasaurus）和三疣龙（Sanjuansaurus）。

The last meat-eater Eodromaeus was the size of a large bird.

最后一种食肉动物曙奔龙（Eodromaeus）有一只大鸟那么大。

The two others, Eoraptor and Chromogisaurus, were also around the size of a large bird.

另外两只，猛龙（Eoraptor）和蝶龙（Chromogisaurus），也大约是一只大鸟的大小。

They were the ancestors of long-necked, four-legged large dinosaurs like Argentinosaurus and Dreadnoughtus.

它们是阿根廷龙（Argentinosaurus）和无畏龙（Dreadnoughtus）等长脖子、四条腿的大型恐龙的祖先。

All five showed signs of fast growth.

这五种化石都显示出快速增长的迹象。

But the researchers also surprisingly found that some non-dinosaur reptiles in the same area and time had their own fast growth rates.

但研究人员也令人惊讶地发现，在同一地区和同一时间，一些非恐龙爬行动物也有快速生长迹象。

Quick growth was also found in four-legged Saurosuchus.

四条腿的蜥鳄被发现也长得很快

It was a top-level meat-eater on land that was 7 meters long and similar to a reptile found today, the crocodile.

它是陆地上顶级的食肉动物，长达7米，与今天发现的爬行动物---鳄鱼相似。

Additionally, quick growth was found in crocodile relatives like Proterochampsa and Trialestes.

此外，在像原鳄龙属（Proterochampsa）和三叠鳄属（Trialestes）这样的鳄鱼近亲中发现了快速生长。

Other animals like the planting-eating reptile Hyperodapedon and mammal-like reptile Exaeretodon also grew quickly.

其他动物，如以植物为食的爬行动物超咬吞蜥（Hyperodapedon）和类似哺乳动物的爬行动物Exaeretodon也生长迅速。

But they regularly paused their growth throughout their life.

但在他们的一生中，他们经常暂停成长。

That is different than the continuous fast growth of dinosaurs.

这一点与恐龙的持续快速增长不同。

The first dinosaurs and these other animals evolved during a time on earth called the Triassic Period.

最早的恐龙和其他动物是在地球上一个被称为三叠纪的时期进化出来的。

It followed after Earth's worst mass extinction 252 million years ago at the end of the Permian Period.

在2.52亿年前地球上最严重的大灭绝之后，紧随着就是二叠纪末期。

About 95 percent of different kinds of animals were lost after severe climate change.

在严重的气候变化之后，大约95%的不同种类的动物消失了。

The climate change may have been caused by massive volcanic activity in an area found in today's Russia.

气候变化可能是由今天俄罗斯发现的一个地区的大规模火山活动引起的。

Curry Rogers said that fast growth was good for them in a changing world.

库里·罗杰斯说，在一个不断变化的世界里，快速增长对他们来说是件好事。

And she said that fast growth combined with dinosaur biology and behavior allowed dinosaurs to succeed early.

她说，快速的生长与恐龙的生物学和行为相结合，使得恐龙很早就成功了。

Another mass extinction at the end of the Triassic about 201 million years ago killed off many early competitors to the dinosaurs.

另一次大规模灭绝发生在大约2.01亿年前的三叠纪末期，导致恐龙的许多早期竞争者死亡。

Curry Rogers said that as time continued, dinosaurs held onto these high growth rates.

库里·罗杰斯说，随着时间的推移，恐龙保持着这样的高增长率。

She said that lead to many different kinds of dinosaurs.

她说，这衍生了许多不同种类的恐龙。

But she said their competitors, like crocodile-cousins, had less differences in growth patterns and behavior.

但她说，它们的竞争对手，如鳄鱼的近亲，在增长模式和行为上的与之差异较小。

I'm Gregory Stachel.

我是格雷戈里·斯塔切尔。