2022年12月09日 VOA慢速英語：科學(xué)家：遠古生物的生長速度比預(yù)期的要快

 

Long before the time of the dinosaurs, an unusual creature called Whatcheeria was a top predator.
早在恐龍時代之前，一種名為 Whatcheria 的不尋常生物就是頂級捕食者。
 
New research is providing a deeper understanding of Whatcheeria, which lived around 330 million years ago during a time known as the Carboniferous period.
新的研究使人們對Whatcheeria，生活在大約 3.3 億年前的石炭紀時期。
 
After a close examination of the creature's ancient bones, scientists were surprised to find that Whatcheeria did not grow slowly and continuously like modern reptiles and amphibians. Instead, the creature grew quickly while young, like birds and mammals.
在仔細檢查了這種生物的古老骨骼后，科學(xué)家們驚訝地發(fā)現(xiàn)，Whatcheria 并不像現(xiàn)代爬行動物和兩棲動物那樣緩慢而持續(xù)地生長。取而代之的是，這種生物在年輕時生長迅速，就像鳥類和哺乳動物一樣。
 
Whatcheeria was an early tetrapod, as the first land animals with backbones were known. These were the ancestors of today's land vertebrates – animals such as amphibians, reptiles, birds and mammals.
Whatcheria 是一種早期的四足動物，因為人們知道第一批有脊椎的陸生動物。它們是當今陸地脊椎動物——兩棲動物、爬行動物、鳥類和哺乳動物等動物的祖先。
 
Spending much of its time in lakes and rivers, Whatcheeria reached about 2 meters long, making it the biggest predator at the time.
大部分時間都在湖泊和河流中度過，Whatcheria 身長約 2 米，是最大的捕食者當時。
 
Megan Whitney of Loyola University in Chicago was the lead writer of the study that recently appeared in Communications Biology. She said, "Whatcheeria was not a slow... oversized amphibian." It was, she added, an active predator that grew quickly in the early part of its life.
芝加哥洛約拉大學(xué)的梅根·惠特尼 (Megan Whitney) 是該研究的主要作者，該研究最近發(fā)表在通訊生物學(xué)雜志上。她說，“Whatcheria 不是一種緩慢的……超大的兩棲動物。”她補充說，它是一種活躍的捕食者，在其生命的早期階段生長迅速。
 
Whatcheeria's name comes from the nearly 400 fossils found near the small Iowa town of What Cheer. The creature had a large skull filled with teeth as well as large limbs. Whitney said it was the top "predator of its environment that included different kinds of ancient fish and sharks as well as other, smaller early tetrapods."
Whatcheria 的名字來源于在愛荷華州 What Cheer 小鎮(zhèn)附近發(fā)現(xiàn)的近 400 塊化石。這個生物有一個長滿牙齒的大頭骨和粗壯的四肢?；萏啬嵴f，它是“其環(huán)境中的頂級捕食者，包括不同種類的古代魚類和鯊魚以及其他較小的早期四足動物。”
 
Unlike many early tetrapods, bones of Whatcheeria have been discovered from different points in the animal's life. "Bones act as storybooks, recording information about animals while they're alive. And one of the important pieces of information that is recorded in bone is how fast the animal is growing," Whitney said.
與許多早期的四足動物不同，Whatcheria 的骨骼是在動物生命的不同階段被發(fā)現(xiàn)的。 Whitney 說：“骨頭就像故事書，記錄了動物活著時的信息。骨骼中記錄的重要信息之一就是動物的生長速度。”
 
A careful study of pieces of thigh bones from nine Whatcheeria individuals showed bone growth over time.
A仔細研究 9 個 Whatcheeria 個體的大腿骨碎片表明，骨骼會隨著時間的推移而生長。
 
"A key finding of this research is that we identified fast-growing bone in juveniles of Whatcheeria. This is important because it indicates that the growth strategy of this animal was similar to ours: grow fast while young and then slow down growth as you become an adult," Whitney said.
“這項研究的一個重要發(fā)現(xiàn)是，我們在 Whatcheeria 的幼魚中發(fā)現(xiàn)了快速生長的骨骼。這很重要，因為它表明這種動物的生長策略與我們的相似：在年輕時快速生長，然后隨著年齡的增長而減慢生長速度惠特尼說。
 
She added that this kind of growth has long been considered special to warm-blooded animals like mammals and birds. However, Whitney added, "what we were able to show here is that this strategy was used even at the earliest stages of our evolutionary history."
她補充說，長期以來，這種生長一直被認為是哺乳動物和鳥類等溫血動物所特有的。然而，惠特尼補充說，“我們在這里能夠展示的是，這種策略甚至在我們進化史的最早階段就被使用過。”
 
As a predator, Whitney said, Whatcheeria could have used a number "of hunting techniques." Researchers were not sure how much time the creature spent hunting on land or water. But the study showed that the animal could walk on land.
研究人員不確定這種生物花了多少時間在陸地或水上狩獵。但研究表明，這種動物可以在陸地上行走。
Ben Otoo is a co-writer of the study. He added that "Whatcheeria is a really nice demonstration
that evolution isn't linear."
Ben Otoo 是該研究的合著者。他補充說，“Whatcheria 很好地證明了進化不是線性的。”