溫血還是冷血?恐龍介於兩者之間_科學探索_太平洋電腦網資訊中心

原文地址：http://news.yahoo.com/warm-blooded-cold-dinosaurs-were-somewhere-between-201115255.html

原創翻譯：龍騰網 http://www.ltaaa.com 

正文翻譯：

Warm blooded or cold? Dinosaurs were somewhere in between

溫血還是冷血？恐龍介於兩者之間

The dinosaur named "Sue," a 41-foot-long Tyrannosaurus rex, is shown on display at the Field Museum in Chicago, Illinois in this May 17, 2000 file photo. REUTERS/Sue Ogrocki/Files 

3月17號，這條叫做"蘇"的41英尺長的霸王龍正在伊利諾州的芝加哥自然博物館中展示。

WASHINGTON (Reuters) - The hot question of whether dinosaurs were warm-blooded like birds and mammals or cold blooded like reptiles, fish and amphibians finally has a good answer.

路透社華盛頓報導，關於恐龍到底是像哺乳動物或者鳥這樣的恆溫動物，還是像爬行，兩棲類或者魚這樣的變溫動物，這個問題終於有了一個合理的答案， 

Dinosaurs, for eons Earth's dominant land animals until being wiped out by an asteroid 65 million years ago, were in fact somewhere in between.

恐龍，6500萬年前被一顆小行星滅絕的遠古地球大陸上曾經的統治者，事實上介於這兩者之間。

Scientists said on Thursday they evaluated the metabolism of numerous dinosaurs using a formula based on their body mass as revealed by the bulk of their thigh bones and their growth rates as shown by growth rings in fossil bones akin to those in trees.

周四科學家表示他們通過建立一個公式揭示了大量恐龍生前的新陳代謝方式和他們巨大身軀尺寸之間的關係，這個尺寸的測量是根據恐龍化石裡大腿骨的長度和恐龍生長過程中骨頭髮育留下的痕跡，就像樹的年輪一樣。 

The study, published in the journal Science, assessed 21 species of dinosaurs including super predators Tyrannosaurus and Allosaurus, long-necked Apatosaurus, duckbilled Tenontosaurus and bird-like Troodon as well as a range of mammals, birds, bony fish, sharks, lizards, snakes and crocodiles.

這項研究刊登在科學雜誌上，包括對21種恐龍的研究，其中有超級食肉動物霸王龍、異龍，長脖子的雷龍，長著鴨嘴的腱龍和像鳥一樣纖細的傷齒龍，同時還有和一部分哺乳動物，鳥，硬骨魚，鯊魚，蜥蜴，蛇，鱷魚的對比。

"Our results showed that dinosaurs had growth and metabolic rates that were actually not characteristic of warm-blooded or even cold-blooded organisms. They did not act like mammals or birds nor did they act like reptiles or fish," said University of Arizona evolutionary biologist and ecologist Brian Enquist.

"我們的研究顯示恐龍新陳代謝的方式和恆溫動物或者變溫動物都不一樣。他們既不像哺乳動物，又不像鳥，爬行動物或者魚，"亞利桑那大學的生物進化學家和生態學家Brian Enquist說。 

"Instead, they had growth rates and metabolisms intermediate to warm-blooded and cold-blooded organisms of today. In short, they had physiologies that are not common in today's world."

"或者說，他們的新陳代謝方式介於溫血動物和冷血動物之間，直接一點講就是，現在這個地球上的生物裡是找不到它們這樣的生理性狀的。" 

There has been a long-standing debate about whether dinosaurs were slow, lumbering cold-blooded animals - as scientists first proposed in the 19th century - or had a uniquely advanced, more warm-blooded physiology.

關於恐龍是不是一種緩慢笨拙的冷血動物，曾經有過長期的爭論——科學家在19世紀曾經大都是這樣認為的，同時有人認為其從生理上來說是一種獨特的溫血動物。

As scientists unearthed remains of more and more fast-looking dinosaurs like Velociraptor, some championed the idea dinosaurs were as active and warm–blooded as mammals and birds. The realization that birds arose from small feathered dinosaurs seemed to support that view.

隨著越來越多的行動迅速的恐龍，比如說速龍被發掘出來，有些人開始擁護恐龍像哺乳動物和鳥一樣是溫血動物這種觀點。關於鳥可能是長著羽毛的小型恐龍這一認識似乎在支持這種觀點。

University of New Mexico biologist John Grady said the idea that creatures must be either warm-blooded or cold-blooded is too simplistic when looking over the vast expanse of time. Like dinosaurs, some animals alive today like the great white shark, leatherback sea turtle and tuna do not fit easily into either category, Grady added.

新墨西哥州立大學的生物學家John Grady表達了這樣一種觀點：簡單地把生物分為溫血或者冷血這種說法似乎太絕對了，就算是現在的生物，比如大白鯊，稜皮龜或者金槍魚之類動物都不完全符合這種分類方式，他補充。

"A better answer would be 'in the middle.' By examining animal growth and rates of energy use, we were able to reconstruct a metabolic continuum, and place dinosaurs along that continuum. Somewhat surprisingly, dinosaurs fell right in the middle," Grady said.

"更好的答案是介於兩者之間，在對生物的生長和能量利用方面的研究中，可以發現新陳代謝的過程都是連續的,出人意料的是，將恐龍列入這個範疇之內，你會發現它們的新陳代謝方式剛好介於兩者之間。"Grady說 

The researchers called creatures with this medium-powered metabolism mesotherms, as contrasted to ectotherms (cold–blooded animals with low metabolic rates that do not produce much heat and bask in the sun to warm up) and endotherms (warm–blooded animals that use heat from metabolic reactions to maintain a high, stable body temperature).

研究者把這種利用能量的方式介於兩者之間的生物稱為中溫動物，和變溫動物（冷血而保持低新陳代謝率的動物，用曬太陽來提高體溫）與恆溫動物（溫血的，用提高新陳代謝率來保持高而穩定的體溫的動物）相區分。 

Grady said an intermediate metabolism may have allowed dinosaurs to get much bigger than any mammal ever could. Warm–blooded animals need to eat a lot so they are frequently hunting or munching on plants. "It is doubtful that a lion the size of T. rex could eat enough to survive," Grady said.

Grady說這種處於兩者之間的新陳代謝方式使得恐龍可以長得比哺乳動物大得多，恆溫動物必須攝入很多食物，頻繁地捕獵或吃植物，"一隻像霸王龍那樣大的獅子是不可能得到足夠食物來活命的"Grady說。 

評論翻譯：

Wooly mammoths were about the size of a T Rex, and they survived very weil in Arctic conditions. There is some advantage in being large, since large animals radiate less heat per weight. 

長毛的猛獁可以長得跟霸王龍一樣大，而且在北極的環境中活得很好，長得大還是有好處的，同樣的體重可以保存更多的熱量。

Considering that Earth's overall climate was much hotter than it is now...What do we grade to the blood temperatures of dinosaurs against as an average

考慮到世界正在變暖，如果我們血液的溫度變成恐龍這樣會怎麼樣呢？