研究证明，十几岁的雷克斯暴龙也有发育高峰

Putting to bed the theory that there was a pygmy species of Tyrannosaurus rex, a new study has confirmed the most fearsome dinosaur to ever walk the Earth underwent a massive growth spurt as a teenager.

一项新的研究证实，地球上有史以来最可怕的恐龙在十几岁时经历了一次巨大的生长突增，彻底推翻了霸王龙是侏儒种的理论。

The research, published in Science Advances, shows that the two fossils discovered in the early 21st century — known as Jane and Petey — were approximately 13 and 15 years old, respectively, and only slightly taller than a modern-day draft horse and twice as long. By comparison, a full-grown adult T. rex could reach 40 feet in length.

这项发表在《科学进展》杂志上的研究表明，21世纪初发现的两块化石——简和皮蒂——分别大约有13岁和15岁，只比现代的役用马高一点，长度是现在的两倍。相比之下，成年霸王龙身长可达40英尺。

“Historically, many museums would collect the biggest, most impressive fossils of a dinosaur species for display and ignore the others,” said the study’s lead author, Holly Woodward, in a statement. “The problem is that those smaller fossils may be from younger animals. So, for a long while we’ve had large gaps in our understanding of how dinosaurs grew up, and T. rex is no exception.”

“从历史上看，许多博物馆会收集最大、最令人印象深刻的恐龙化石来展示，而忽略了其他的，”该研究的第一作者霍利伍德沃德(Holly Woodward)在一份声明中说。“问题是那些较小的化石可能来自更年轻的动物。所以，很长一段时间以来，我们对恐龙是如何长大的了解有很大的差距，雷克斯霸王龙也不例外。”

It was originally believed that Jane and Petey were a “pygymy” version of the T. rex, known as Nanotyrannus.

人们最初认为简和皮蒂是矮暴龙的矮人偶。

Woodward and the other researchers looked at the bone structure of Jane and Petey and counted the annual growth rings in the fossils to determine their age and that they were not a subspecies of T. rex, but rather small teenagers. Woodward added that the discovery will likely aid other paleontologists in learning how the bones and proportions of these massive dinosaurs changed as they grew older.

伍德沃德和其他研究人员观察了简和皮蒂的骨骼结构，计算了化石上的年轮以确定它们的年龄，他们不是霸王龙的亚种，而是年幼的青少年。伍德沃德补充说，这一发现可能会帮助其他古生物学家了解这些巨型恐龙的骨骼和比例是如何随着年龄的增长而变化的。

“To me, it’s always amazing to find that if you have something like a huge fossilized dinosaur bone, it’s fossilized on the microscopic level as well,” Woodward said. “And by comparing these fossilized microstructures to similar features found in modern bone, we know they provide clues to metabolism, growth rate, and age.”

伍德沃德说:“对我来说，如果你发现一块巨大的恐龙骨骼化石，它在微观层面上也会变成化石，这总是令人惊讶的。”“通过比较这些化石的微观结构和现代骨骼的相似特征，我们知道它们为新陈代谢、生长速度和年龄提供了线索。”

Since these were fast dinosaurs, with razor-sharp teeth, the abundance of food was of great importance to their growth rates, Woodward suggested. If food was scarce, its growth levels tapered off and if it was abundant, its growth rate soared.

伍德沃德认为，由于这些恐龙行动迅速，牙齿锋利，充足的食物对它们的生长速度至关重要。如果食物匮乏，它的生长水平就会逐渐下降;如果食物充足，它的生长速度就会飙升。

It’s believed that it took up to 20 years for a T. rex to reach full adulthood, adding greater importance to the spacing between the rings in the bones, Woodward continued.

伍德沃德接着说，人们认为霸王龙要花20年的时间才能完全成年，这使得骨骼中年轮之间的距离更加重要。

“The spacing between annual growth rings record how much an individual grows from one year to the next,” Woodward said. “The spacing between the rings within Jane, Petey, and even older individuals is inconsistent—some years the spacing is close together, and other years it’s spread apart.”

伍德沃德说:“年轮之间的间隔记录了一个人从一年到下一年的生长速度。”“简，皮特，甚至更年长的人的年轮之间的间隔是不一致的——有些年份间隔很近，有些年份间隔很长。”

In September, a study was published that suggested the terrifying dinosaur had a stiff skull that allowed it to not shatter its own bones with its bite force, while simultaneously devouring its kill.

9月发表的一项研究表明，这种可怕的恐龙有一个坚硬的头骨，使它在吞食猎物的同时不会用咬合力打碎自己的骨头。

In addition to having a stiff skull, T. rex likely had something similar to an “air conditioner” in its head, allowing it to stay cool while hunting, according to a separate study.

根据另一项研究，除了拥有坚硬的头骨外，雷克斯霸王龙的脑袋里可能还有类似于“空调”的东西，可以让它在狩猎时保持凉爽。