研究證明，十幾歲的雷克斯暴龍也有發(fā)育高峰

研究證明，十幾歲的雷克斯暴龍也有發(fā)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.

一項新的研究證實，地球上有史以來最可怕的恐龍在十幾歲時經歷了一次巨大的生長突增，徹底推翻了霸王龍是侏儒種的理論。

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.

這項發(fā)表在《科學進展》雜志上的研究表明，21世紀初發(fā)現(xiàn)的兩塊化石——簡和皮蒂——分別大約有13歲和15歲，只比現(xiàn)代的役用馬高一點，長度是現(xiàn)在的兩倍。相比之下，成年霸王龍身長可達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.”

“從歷史上看，許多博物館會收集最大、最令人印象深刻的恐龍化石來展示，而忽略了其他的，”該研究的第一作者霍利伍德沃德(Holly Woodward)在一份聲明中說。“問題是那些較小的化石可能來自更年輕的動物。所以，很長一段時間以來，我們對恐龍是如何長大的了解有很大的差距，雷克斯霸王龍也不例外。”

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

人們最初認為簡和皮蒂是矮暴龍的矮人偶。

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員觀察了簡和皮蒂的骨骼結構，計算了化石上的年輪以確定它們的年齡，他們不是霸王龍的亞種，而是年幼的青少年。伍德沃德補充說，這一發(fā)現(xiàn)可能會幫助其他古生物學家了解這些巨型恐龍的骨骼和比例是如何隨著年齡的增長而變化的。

“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.”

伍德沃德說:“對我來說，如果你發(fā)現(xiàn)一塊巨大的恐龍骨骼化石，它在微觀層面上也會變成化石，這總是令人驚訝的。”“通過比較這些化石的微觀結構和現(xiàn)代骨骼的相似特征，我們知道它們?yōu)樾玛惔x、生長速度和年齡提供了線索。”

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.

伍德沃德認為，由于這些恐龍行動迅速，牙齒鋒利，充足的食物對它們的生長速度至關重要。如果食物匱乏，它的生長水平就會逐漸下降;如果食物充足，它的生長速度就會飆升。

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.

伍德沃德接著說，人們認為霸王龍要花20年的時間才能完全成年，這使得骨骼中年輪之間的距離更加重要。

“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.”

伍德沃德說:“年輪之間的間隔記錄了一個人從一年到下一年的生長速度。”“簡，皮特，甚至更年長的人的年輪之間的間隔是不一致的——有些年份間隔很近，有些年份間隔很長。”

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月發(fā)表的一項研究表明，這種可怕的恐龍有一個堅硬的頭骨，使它在吞食獵物的同時不會用咬合力打碎自己的骨頭。

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.

根據(jù)另一項研究，除了擁有堅硬的頭骨外，雷克斯霸王龍的腦袋里可能還有類似于“空調”的東西，可以讓它在狩獵時保持涼爽。