時差N小時:害怕被劍齒虎咬

Don：Hey, Yale. Would you rather be bitten by asaber-toothed tiger or a modern day tiger?

唐：嘿，雅艾爾。你寧愿被劍齒虎咬還是被現(xiàn)代的老虎咬?

Yael：Neither, of course. But if I have to pick, Isupposed I choose the modern tiger. Since thesaber-toothed tiger massive fangs.

雅艾爾：都不愿意。如果一定要選的話，我情愿選現(xiàn)代的老虎。因為劍齒虎長有巨大的獠牙。

Don：Well, you may be surprised to learn that paleontologists now think that despite theirhuge, fearsome looking canine teeth, the prehistoric American sabercat, Smilodon fatalis,had a bite force only about one-third as strong as modern big cats.

唐：不過，古生物學(xué)家認為除了巨大的、長相可怕的犬齒之外，美國史前劍齒虎 Smilodon fatalis 的咬合力只有現(xiàn)代大貓的三分之一，知道這一點你可能會覺得很驚訝。

Yael：How can they told that from fossilized bones?

雅艾爾：他們是如何根據(jù)骨頭化石得知咬合力的?

Don：They used very fine CT scans of the skull, jaw and neck bones to create a highlydetailed 3 D computer model. Then using careful analysis of the size and placement of muscleattachment points and mathematical modeling they were able to calculate the power of thejaw muscles and the bite force of the now extinct sabercats. This was the most detailedcomputer model ever created for a vertebrate.

唐：他們用精密的CT掃描儀掃描頭骨，顎和頸椎骨，用來建立一個高度精確的3D電腦模型。然后仔細分析肌肉附著點的尺寸和位置，利用這些數(shù)據(jù)進行數(shù)學(xué)建模，這樣他們才能夠計算出目前已經(jīng)滅絕的劍齒虎的顎肌的力量和咬合力。這是人們迄今建立的最精確的脊椎動物電腦模型。

Yael：Neat! So if they had such a wimpy bite, what's with the huge fangs?

雅艾爾：做得好!那么如果它們的咬合力小，那么這些獠牙還有何用?

Don：The function of the sabercat's eight inch teeth is one of the longest running debates inpaleontology. The results of this study support the hypothesis that the sabercats broughtdown and subdued large prey, like mammoths, with their strong forelimbs. Once the prey wassafely restrained on the ground, sabercats used their large fangs to pierce through the thickhide on the neck of their quarry. In contrast, modern day big cats use their more powerfuljaws to bite the neck of their prey for an extended period to subdue them by asphyxiation.

唐：劍齒虎的門牙有八英尺長，至于它的作用至今仍是古生物學(xué)屆最持久的爭議話題之一。這項研究的結(jié)果支持這種假說：劍齒虎使用強壯的前肢撲倒和制服像猛犸象這樣的大型獵物。一旦獵物被徹底制服在地上，劍齒虎便用它那巨大的獠牙刺穿獵物脖子上的厚皮。相反，現(xiàn)代的大貓則利用更鋒利的顎來長時間咬住獵物的脖子，直到它們窒息而亡。

Yael：Yikes!I think I'll pass on being bitten by either a sabercat or a modern day tiger.

雅艾爾：呀!我想在劍齒虎或者現(xiàn)代老虎咬我的時候，我就會不行了。

Don：Wise choice.

唐：明智的選擇。