Dinosaurs existed for 165 million years. The animals' evolutionary success was partly due to their fast growth rate.
恐龙存在了1.65亿年。这种动物在进化上的成功部分是由于它们的快速生长速度。
A new study finds that this pattern of fast growth appeared in the earliest dinosaurs. The researchers examined microscopic details in dinosaur bone fossils from Argentina.
一项新的研究发现，这种快速生长的模式出现在最早的恐龙身上。研究人员检查了阿根廷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.
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. She is the lead writer of the research recently released in the publication PLOS ONE.
明尼苏达州马卡莱斯特学院的科学家克里斯蒂·库里·罗杰斯研究化石。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要作者。
She said, "Growing quickly allows organisms to escape the risky business of being small for a long part of their life history." And she added that it also allows them to reproduce more throughout their life. That means each following generation will be more successful.
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避体型小的风险。”她补充说，这也使它们在一生中繁殖更多。这意味着下一代会更成功。
The researchers examined patterns fossilized within the bones of dinosaurs and some of their relatives. The dinosaurs they looked at lived in northwestern Argentina between 231 and 229 million years ago.
研究人员检查了恐龙及其一些近亲骨骼中的化石模式。他们研究的恐龙生活在2.31亿到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. 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.
库里·罗杰斯说，化石中的细胞和化学细节都显示了相对的生长速度。她补充说，动物的柔软部分已经不复存在，但像骨头这样的硬部分留下了柔软部分曾经存在的空间记录。
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. They all walked on two feet, were quick on their feet, had clawed hands that could hold objects and had sharp teeth.
研究人员研究了五种早期恐龙。他们都用两只脚走路，速度很快，有能抓东西的爪状手，还有锋利的牙齿。
Three were meat-eaters and the ancestors of large meat-eaters like T. rex and Giganotosaurus. The dinosaurs included Herrerasaurus and Sanjuansaurus which were around 3-4.5 meters long. The last meat-eater Eodromaeus was the size of a large bird.
其中三种是食肉动物，是霸王龙和南方巨兽龙等大型食肉动物的祖先。这些恐龙包括埃雷拉龙和三柱龙，身长约3-4.5米。最后的食肉动物欧卓玛厄有一只大鸟那么大。
The two others, Eoraptor and Chromogisaurus, were also around the size of a large bird. They were the ancestors of long-necked, four-legged large dinosaurs like Argentinosaurus and Dreadnoughtus.
另外两种，盗龙和色龙，也和一只大鸟差不多大。它们是阿根廷龙和无畏龙等长颈四足大型恐龙的祖先。
All five showed signs of fast growth.
这五个国家都显示出了快速增长的迹象。
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自己的快速生长速度。
Quick growth was also found in four-legged Saurosuchus. It was a top-level meat-eater on land that was 7 meters long and similar to a reptile found today, the crocodile. Additionally, quick growth was found in crocodile relatives like Proterochampsa and Trialestes.
四足龙的生长速度也很快。它是陆地上的顶级食肉动物，身长7米，类似于今天发现的爬行动物——鳄鱼。此外，在鳄鱼的近亲中发现了快速生长的鳄鱼，如原鳄和Trialestes。
Other animals like the planting-eating reptile Hyperodapedon and mammal-like reptile Exaeretodon also grew quickly. But they regularly paused their growth throughout their life. That is different than the continuous fast growth of dinosaurs.
其他动物，如植食性爬行动物超足类和类哺乳动物爬行动物无齿兽也生长得很快。但它们在一生中会定期停止生长。这与恐龙的持续快速生长不同。
The first dinosaurs and these other animals evolved during a time on earth called the Triassic Period. It followed after Earth's worst mass extinction 252 million years ago at the end of the Permian Period.
最早的恐龙和其他动物是在地球上的三叠纪时期进化的。它发生在2.52亿年前二叠纪末期地球上最严重的物种大灭绝之后。
About 95 percent of different kinds of animals were lost after severe climate change. The climate change may have been caused by massive volcanic activity in an area found in today's Russia.
在严重的气候变化之后，大约95%的不同种类的动物消失了。气候变化可能是由今天俄罗斯境内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. And she said that fast growth combined with dinosaur biology and behavior allowed dinosaurs to succeed early.
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。她说，恐龙的快速生长与恐龙的生物学和行为相结合，使恐龙很早就成功了。
Another mass extinction at the end of the Triassic about 201 million years ago killed off many early competitors to the dinosaurs.
另一次大灭绝发生在大约2.01亿年前的三叠纪末期，杀死了许多恐龙的早期竞争对手。
Curry Rogers said that as time continued, dinosaurs held onto these high growth rates. She said that lead to many different kinds of dinosaurs. But she said their competitors, like crocodile-cousins, had less differences in growth patterns and behavior.
库里·罗杰斯说，随着时间的推移，恐龙保持了这样高的生长速度。她说，这导致了许多不同种类的恐龙。但她说，它们的竞争对手，比如鳄鱼的表亲，在生长模式和行为上的差异较小。
恐龙存在了1.65亿年。这种动物在进化上的成功部分是由于它们的快速生长速度。
A new study finds that this pattern of fast growth appeared in the earliest dinosaurs. The researchers examined microscopic details in dinosaur bone fossils from Argentina.
一项新的研究发现，这种快速生长的模式出现在最早的恐龙身上。研究人员检查了阿根廷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.
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. She is the lead writer of the research recently released in the publication PLOS ONE.
明尼苏达州马卡莱斯特学院的科学家克里斯蒂·库里·罗杰斯研究化石。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要作者。
She said, "Growing quickly allows organisms to escape the risky business of being small for a long part of their life history." And she added that it also allows them to reproduce more throughout their life. That means each following generation will be more successful.
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避体型小的风险。”她补充说，这也使它们在一生中繁殖更多。这意味着下一代会更成功。
The researchers examined patterns fossilized within the bones of dinosaurs and some of their relatives. The dinosaurs they looked at lived in northwestern Argentina between 231 and 229 million years ago.
研究人员检查了恐龙及其一些近亲骨骼中的化石模式。他们研究的恐龙生活在2.31亿到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. 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.
库里·罗杰斯说，化石中的细胞和化学细节都显示了相对的生长速度。她补充说，动物的柔软部分已经不复存在，但像骨头这样的硬部分留下了柔软部分曾经存在的空间记录。
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. They all walked on two feet, were quick on their feet, had clawed hands that could hold objects and had sharp teeth.
研究人员研究了五种早期恐龙。他们都用两只脚走路，速度很快，有能抓东西的爪状手，还有锋利的牙齿。
Three were meat-eaters and the ancestors of large meat-eaters like T. rex and Giganotosaurus. The dinosaurs included Herrerasaurus and Sanjuansaurus which were around 3-4.5 meters long. The last meat-eater Eodromaeus was the size of a large bird.
其中三种是食肉动物，是霸王龙和南方巨兽龙等大型食肉动物的祖先。这些恐龙包括埃雷拉龙和三柱龙，身长约3-4.5米。最后的食肉动物欧卓玛厄有一只大鸟那么大。
The two others, Eoraptor and Chromogisaurus, were also around the size of a large bird. They were the ancestors of long-necked, four-legged large dinosaurs like Argentinosaurus and Dreadnoughtus.
另外两种，盗龙和色龙，也和一只大鸟差不多大。它们是阿根廷龙和无畏龙等长颈四足大型恐龙的祖先。
All five showed signs of fast growth.
这五个国家都显示出了快速增长的迹象。
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自己的快速生长速度。
Quick growth was also found in four-legged Saurosuchus. It was a top-level meat-eater on land that was 7 meters long and similar to a reptile found today, the crocodile. Additionally, quick growth was found in crocodile relatives like Proterochampsa and Trialestes.
四足龙的生长速度也很快。它是陆地上的顶级食肉动物，身长7米，类似于今天发现的爬行动物——鳄鱼。此外，在鳄鱼的近亲中发现了快速生长的鳄鱼，如原鳄和Trialestes。
Other animals like the planting-eating reptile Hyperodapedon and mammal-like reptile Exaeretodon also grew quickly. But they regularly paused their growth throughout their life. That is different than the continuous fast growth of dinosaurs.
其他动物，如植食性爬行动物超足类和类哺乳动物爬行动物无齿兽也生长得很快。但它们在一生中会定期停止生长。这与恐龙的持续快速生长不同。
The first dinosaurs and these other animals evolved during a time on earth called the Triassic Period. It followed after Earth's worst mass extinction 252 million years ago at the end of the Permian Period.
最早的恐龙和其他动物是在地球上的三叠纪时期进化的。它发生在2.52亿年前二叠纪末期地球上最严重的物种大灭绝之后。
About 95 percent of different kinds of animals were lost after severe climate change. The climate change may have been caused by massive volcanic activity in an area found in today's Russia.
在严重的气候变化之后，大约95%的不同种类的动物消失了。气候变化可能是由今天俄罗斯境内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. And she said that fast growth combined with dinosaur biology and behavior allowed dinosaurs to succeed early.
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。她说，恐龙的快速生长与恐龙的生物学和行为相结合，使恐龙很早就成功了。
Another mass extinction at the end of the Triassic about 201 million years ago killed off many early competitors to the dinosaurs.
另一次大灭绝发生在大约2.01亿年前的三叠纪末期，杀死了许多恐龙的早期竞争对手。
Curry Rogers said that as time continued, dinosaurs held onto these high growth rates. She said that lead to many different kinds of dinosaurs. But she said their competitors, like crocodile-cousins, had less differences in growth patterns and behavior.
库里·罗杰斯说，随着时间的推移，恐龙保持了这样高的生长速度。她说，这导致了许多不同种类的恐龙。但她说，它们的竞争对手，比如鳄鱼的表亲，在生长模式和行为上的差异较小。
