VOA慢速英语2019 研究提供了有关青少年霸王龙的新细节（在线收听）

Study Provides New Details about Teenage T. Rex

Scientists say they have discovered new details about young Tyrannosaurus rex dinosaurs.

科学家说，他们发现了有关幼霸王龙恐龙的新细节。

Researchers examined fossilized skeleton samples from two small Tyrannosaurus rex – also known as T. rex. The skeletons were discovered in the western American state of Montana in the early 2000s.

研究人员检查了两只小霸王龙（也称为霸王龙）的化石骨架样本。这些骨骼是在2000年代初期在美国西部的蒙大拿州发现的。

Researchers named the two dinosaurs Jane and Petey. Each T. rex was estimated to have stood a little taller than a horse and was about twice as long.

研究人员将这两个恐龙命名为Jane和Petey。据估计，每只霸王龙都比马高一些，长约两倍。

The researchers say the fossilized bone samples have helped them better understand the history and development of this famous dinosaur. The findings are described in a study recently published in Science Advances.

研究人员说，化石骨骼样本帮助他们更好地了解了这种著名恐龙的历史和发展。最近发表在《科学进展》上的一项研究中描述了这些发现。

The examination team was led by Oklahoma State University's Center for Health Sciences.

检验小组由俄克拉荷马州立大学健康科学中心领导。

Holly Woodward was a lead writer of the study. She said in a statement that it was unusual to study such small fossils from the T. rex family. This is because researchers usually seek to collect the largest fossil samples they can find to study and to show in public.

霍莉·伍德沃德（Holly Woodward）是该研究的主要作者。她在一份声明中说，研究霸王龙家族的这种小化石是不寻常的。这是因为研究人员通常寻求收集最大的化石样品，以供研究和在公共场合展示。

"The problem is that those smaller fossils may be from younger animals," Woodward said. "So, for a long while we've had large gaps in our understanding of how dinosaurs grew up, and T. rex is no exception."

伍德沃德说：“问题在于，那些较小的化石可能来自年轻的动物。” “因此，很长一段时间以来，我们对恐龙如何成长的理解存在很大差距，霸王龙也不例外。”

The team removed thin pieces from the leg bones of Jane and Petey and examined the samples under a microscope. Woodward said the study of the bones' "microstructure" can provide valuable information about the animals' growth rate, age and metabolism.

该小组从简和皮特的腿骨上去除了细小碎片，并在显微镜下检查了样本。伍德沃德说，对骨骼“微结构”的研究可以提供有关动物生长速度，年龄和新陈代谢的有价值的信息。

Researchers said they were able to use this method to count rings within the fossil bone to estimate age. They said Jane lived to be age 13, while Petey was 15. The size of the blood vessel openings showed the two dinosaurs were still experiencing growth at a fast rate at the time of death.

研究人员说，他们能够使用这种方法对化石骨中的环进行计数，以估计年龄。他们说，简（Jane）活到13岁，而彼特（Pete）才15岁。血管开口的大小显示，两只恐龙在死亡时仍以快速的速度生长。

It takes a T. rex about 20 years to reach adulthood. Fossil evidence shows that when fully grown, the T. rex was about 12 meters long and about 5 meters tall.

霸王龙大约需要20年才能成年。化石证据表明，霸王龙完全长大后，长约12米，高约5米。

The researchers say the samples have already provided important details about young T. rex's growth and development. The fossil examinations suggest the small T. rex grew as fast as modern-day warm-blooded animals such as mammals and birds, the team reported.

研究人员说，这些样品已经提供了有关年轻霸王龙生长发育的重要细节。研究小组报告说，化石检查表明小霸王龙的生长速度与现代温血动物（如哺乳动物和鸟类）一样快。

The researchers said the findings suggest that the teenage T. rex animals were very quick on their feet and had knife-like teeth for cutting. By comparison, the adult T. rex had teeth meant to crush large bones.

研究人员说，研究结果表明，这些少年霸王龙动物的脚步非常快，并且有像刀一样的牙齿可以切割。相比之下，成年霸王龙的牙齿会压碎大骨头。

The researchers said they found a clear link between T. rex growth rates and the availability of food. This was discovered in spacing between the yearly growth rings of the fossil bones.

研究人员说，他们发现霸王龙的生长速度与食物供应之间存在明显的联系。这是在化石骨骼年生环之间的间距中发现的。

"The spacing between the rings within Jane, Petey, and even older individuals is inconsistent," Woodward said. "Some years the spacing is close together, and other years it's spread apart." This finding suggests the T. rex grew less during years in which food supplies were limited. If a large supply of food was available, the T. rex experienced far more growth.

伍德沃德说：“简，皮特乃至年长者中的戒指之间的间距是不一致的。” “有些年份之间的距离很近，而另一些年份则分开了。”这一发现表明，在食物供应有限的年份里，霸王龙的生长减少。如果有大量的食物供应，霸王龙的增长将大大增加。

Some scientists have questioned whether the two small skeletons really came from a T. rex. Those scientists said they believed the two represented evidence of a newfound kind of dinosaur species called Nanotyrannus. The researchers said they believed Nanotyrannus was similar to T. rex, but was smaller and showed different skull and bone development.

一些科学家质疑这两个小骨骼是否真的来自霸王龙。这些科学家说，他们相信这两个代表了一种新发现的恐龙物种，即纳米霸王龙的证据。研究人员说，他们相信纳米霸王龙与霸王龙相似，但更小，显示出不同的头骨和骨骼发育。

But Woodward and her team said the latest evidence from the two examined skeletons suggests they belonged to teenage T rex dinosaurs – not a new species with a smaller body size.

但是伍德沃德和她的团队说，从这两个被检查的骨骼中得到的最新证据表明，它们属于少年霸王龙恐龙，而不是体型较小的新物种。

Words in This Story

gap – n. an empty period between things happening

metabolism – n. the chemical processes by which a plant or an animal uses food and water to grow and heal and to make energy

mammal – n. a kind of animal that feeds milk to its young and that usually has hair or fur covering most of its skin

inconsistent – adj. not staying the same in quality or behavior

skull – n. the bones of the head that surround the brain