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Science & technology
科技板块
Palaeontology
古生物学
Arctic dinosaurs
北极的恐龙
Dinosaurs once flourished near the North Pole
恐龙曾经在北极附近繁盛
Most artistic impressions of dinosaurs picture them in lush forests or on vast temperate savannahs. That is fair enough. Such landscapes were common during the beasts' heydays, the Jurassic and Cretaceous periods. These pictures do, though, ignore the fact that dinosaur fossils have, for decades, been dug up in places which were at that time polar. Whether these are the remains of migrants which came for the summer, or of permanent residents, is debated. But a discovery of bone fragments and teeth from dinosaur hatchlings, just published in Current Biology by Patrick Druckenmiller of University of Alaska, Fairbanks, and his colleagues, suggests some dinosaurs did indeed make their full-time homes in the Arctic.
大多数关于恐龙的艺术印象都是在茂密的森林或广阔的温带草原上。这很合理，因为这样的景观在侏罗纪和白垩纪的野兽鼎盛时期很常见。然而这些照片确实忽略了一个事实，即几十年来恐龙化石都是在当时的极地地区被挖掘出来的。不过这些遗骸究竟是夏天迁过来的移民的还是永久居民的则众说纷纭。而阿拉斯加大学费尔班克斯分校的帕特里克·德鲁肯米勒和他的同事们在《当代生物学》杂志上发表的一项发现表明，恐龙确实在北极安过家。
Modern animals that migrate to polar climes, notably birds, do often breed there. But their eggs hatch quickly and their young develop fast enough to fledge and fly to warmer places before winter arrives. Growth lines in fossilised dinosaur embryos found elsewhere suggest they needed as much as six or seven months of incubation before they were ready to hatch. Palaeontologists therefore reckon any discovery of fossilised eggs or hatchlings near the palaeo-poles would mean the species concerned must have been year-round residents rather than migrants.
迁徙到极地的现代动物，特别是鸟类，通常会在那里繁殖。它们的卵孵化得很快，幼崽也发育得很快，能够在冬天到来之前长出羽毛飞到更温暖的地方。在其他地方发现的恐龙胚胎化石中的生长线表明它们需要6到7个月的孵化期才能孵化。因此古生物学家们认为，任何在古极地附近发现的恐龙蛋或幼仔化石都意味着相关物种一定是永久居民而不是迁徙居民。
译文由可可原创，仅供学习交流使用，未经许可请勿转载。
