Gary Meaney
Originally answered: What was America like during the last ice age?
The most recent Ice Age occurred in the Pleistocene epoch, a time period which started about 2.6 million years ago and ended just ~11,000 years ago. Though it wasn’t very long ago, the world looked very different back then - the wildlife in particular.
I’m going to assume you’re referring to North America - South America too had some amazing and bizarre fauna in the ice age, which probably deserves an answer of its own.
Much of the continent at the time was buried under the enormous Laurentide Ice Sheet, a mass of ice, miles deep, which extended as far south as Illinois.

最初问题:上一个冰河时代的美国是什么样子的?
最近一次冰河时代发生在更新世时期,这个时期开始于260万年前,结束于11000年前。虽然距今不算特别遥远,但世界依然看起来非常不同,特别是野生动物。
我假设你指的是北美。南美洲在冰河时代也有一些神奇而奇异的动物,这可能需要一个它自己的答案。
当时大陆的大部分都被巨大的劳伦德冰原所覆盖,这是一大片高达数英里的冰,一直向南延伸到伊利诺斯州。


Alaska, however, remained largely glacier-free, due to lack of precipitation. As sea levels were much lower (more on that shortly), it was connected to Asia via a landbridge known as Beringia, which allowed animals, and eventually humans, to cross between the two continents.
Today’s Great Lakes, as well as most of Canada’s hundreds of thousands of lakes, were gouged out by the moving ice sheet. And that’s not the only way the great glacier created bodies of water. It was so thick that it redirected moisture-laden winds from the Pacific Ocean further south, to the Southwest region.
As a result of this influx of rainfall, countless lakes formed in California, Nevada, and Utah.

然而,由于缺乏降水,阿拉斯加大部分地区仍然没有冰川。由于海平面(比现在)低得多(稍后会详细介绍),它通过一座名为白令陆桥与亚洲相连,这使得动物,最终是人类,可以在两个大陆之间穿行。
今天的五大湖,以及加拿大数十万个湖泊中的大多数,都是被移动的冰盖凿开的。这并不是大冰川形成水体的唯一方式。它是如此得厚,以至于它把来自太平洋的充满水分的风转向更南的西南地区。
由于降雨的涌入,加州、内华达州和犹他州形成了无数的湖泊。



其中一些是巨大的。例如伯纳威利湖的水面面积超过5万平方公里,是伊利湖的两倍多。大盐湖(如上图)是博纳维尔最后的遗迹。虽然这一地区今天是酷热的沙漠,但在更新世时期它曾郁郁葱葱。
话虽如此,世界上大部分地区比现在更干燥。因为有太多的冰“锁”在冰原中,所以没有那么多的雨水可以流通。这也意味着海平面要低100多米。那时候的北美要大得多,佛罗里达是现在的两倍大:
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不管怎样,让我们谈谈动物。不管是因为人类过度捕猎还是气候变化(我倾向于前者),它们都不像以前那样了。在更新世,有数百种大型动物在世界上游荡,但后来消失了。
不管你信不信,北美曾经是不少于7种大象及其近亲的家园。当然还有著名的长毛猛犸象以及它更大的表亲哥伦比亚猛犸象


A direct descendant of the Columbian mammoth, the pygmy mammoth, dwelt on Santa Rosae, a “superisland” which has now splintered into the Channel Islands of California. This species was a dwarf, due to its island habitat, standing only 2 metres tall. Other species came from other proboscidean families, more distant and alien to the elephants of today. There were two varieties of mastodon, which had a more elongated frx and shorter legs.

哥伦比亚猛犸象的一个直系后裔——侏儒猛犸象,居住在圣罗莎(Santa Rosae),一个“超级岛屿”,现在已经分裂成加利福尼亚的海峡群岛。这个物种是一个侏儒,由于它的岛屿栖息地的限制,站起来只有2米高。
其他物种来自其他长鼻科,与今天的大象更遥远和陌生。乳齿象有两种,它们的骨架较长,腿较短。
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Even stranger were the two surviving species of gomphotheres, which were themselves a separate family. They had huge, spiraling tusks. These were far from the only huge herbivores in North America. As most areas saw a decrease in precipitation, vast tracts of forest gave way to open grassland, the perfect environment for large grazing animals.
Many of the modern American varieties of plant-eaters were much more diverse. As well as today’s bison species, there was the western bison, the antique bison, the steppe bison and the spectacular long-horned bison:

更奇怪的是幸存的两种嵌齿象,它们本身是一个独立的家族。它们有巨大的螺旋状獠牙。它们远远不是北美唯一的大型食草动物。由于大多数地区的降水减少,大片的森林被开阔的草原所取代,这是大型食草动物的完美环境。
许多现代美国食草动物的种类要多样化得多。除了今天的野牛种类外,还有西部野牛、古代野牛、草原野牛和壮观的长角野牛:


Four different relatives of the muskox co-existed, with the so-called giant muskox being the largest. The pronghorn antelope, too, were very diverse. All three of these once-successful lineages - bison, muskox, pronghorn - have now been reduced to one surviving species.
However, no herbivore group saw as dramatic a reduction in species as the horses. There may have been as many as sixteen differen types of native wild horse in North America, whereas now there are none! My favourite is Equus giganteus, a 1.5 tonne beast which was taller at the shoulder than most horses are at the head.

麝牛的四个不同的亲戚同时存在,其中所谓的巨型麝牛是最大的。叉角羚也非常多样化。这三种曾经成功的物种——野牛、麝牛、叉角羚,现在都只剩下一个物种了。
然而,没有任何一组食草动物的物种数量像马那样急剧减少。北美可能曾经有多达16种不同类型的本土野马,而现在一个都没有了!我最喜欢的是巨型马庞马(Equus giganteus),它重1.5吨,肩部比大多数马的头部都要高。

Surprisingly enough, there were also camels in North America during the Pleistocene! Camelops was pretty damn big, too, estimated to have weighed around 800 kg. However, perhaps the strangest North American herbivores of all came from a mammal lineage more typical of South America - the xenarthrans. This includes the famous ground sloths, titanic browsers which could weigh up to a staggering 3 tonnes.
Practically every sloth family produced some kind of giant, ground-dwelling variety. In mainland North America, there were at least seven Pleistocene species, the largest being Eremotherium.

令人惊讶的是,在更新世时期,北美也有骆驼!骆驼也相当大,估计重约800公斤。然而,也许最奇怪的北美食草动物来自一个更典型的南美洲哺乳动物谱系——xenarthrans(异关节总目)。其中包括著名的地懒,体重可达3吨的巨型食草动物。
几乎每一个树懒家族都有某种体型巨大、生活在地面上的物种。在北美大陆,至少有7种更新世物种,最大的是Eremotherium(地懒)。


Another xenarthran group, the armadillos, also featured some wacky beasts. There were two separate families of giant armadillos; the glyptodonts and pampatheres. The latter were distinguished by their more flexible armour. The biggest species was Glyptotherium, which measured six feet in length. Speaking of South American animals being found further north, a lot of modern species which we associate with the former continent were found deep into North America too. Llamas, tapirs, capybaras, peccaries, giant anteaters, ocelots, margays, jaguarundis, and more.
One more very cool animal I should mention before I move on to the carnivores; the giant beaver Castoroides. This genus contained two species, which could perhaps grow to weights of 125 kg!

另一个异关节总目团体——犰狳,也以一些古怪的野兽为特色。巨型犰狳有两个不同的家族——雕齿兽(glyptodonts)和潘帕兽科(pampathere)。



说到在更北的地方发现的南美动物,我们在北美深处也发现了许多与这块前大陆有关的现代物种。美洲驼、貘、水豚、野猪、大食蚁兽、虎猫、美洲山猫等等。
在讲肉食动物之前,我还要提一个很酷的动物——巨型海狸(Cast oroides)。这一属有两种,可以长到125公斤重!


Okay, now for the North American meat-eaters. The most famous were of course the saber-toothed cats. This included the powerful Smilodon fatalis: And the not-quite-so-well-known scimitar cat, Homotherium. There’s evidence that this one may have hunted in groups, like lions do.

现在是北美的肉食动物。最著名的当然是剑齿虎了。还有不太知名的弯刀猫,Homotherium(似剑齿虎属)。有证据表明,这种老虎可能像狮子一样成群狩猎。
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Earlier on in the Pleistocene, North America was home to other saber-toothed species, such as Dinofelis, Megantereon, Metailurus and the unique Xenosmilus. Xenosmilus was massively built, nearly bear-like, and possibly even walked with a plantigrade gait to support its heavy weight.
Its teeth were triangular and serrated, designed not for quickly dispatching prey, but tearing out chunks of flesh and letting blood loss do the rest. They resemble the teeth of sharks in this respect.

在更新世早期,北美是其他剑齿虎物种的家园,如Dinofelis(恐猫属), Megantereon(巨颏虎属), Metailurus(后猫属)和独特的Xenosmilus(异剑齿虎属)。异剑齿虎属体型巨大,几乎像熊一样,甚至可能以跖行步态行走来支撑它的重量。
它的牙齿呈三角形和锯齿状,不是为了快速杀死猎物,而是撕下大块的肉,让失血完成剩下的工作。在这方面,它们的牙齿犹如鲨鱼。

However, these cats had gone extinct by the time human arrived in North America.
In Alaska, there were Eurasian cave lions, which crossed the Bering land bridge. There’s also shaky evidence that there may have been tigers here, if I recall correctly, but it’s certainly not conclusive.
Speaking of lions… the continent had its own special variety, the American lion. About 25% larger than the modern African species, it was one of the largest felines ever to live.

然而,当人类到达北美时,这些猫已经灭绝了。
在阿拉斯加,有欧亚洞穴狮,它们穿过白令海峡大陆桥。如果我没记错的话,也有不可靠的证据表明这里可能有老虎。说到狮子,这片大陆有自己独特的种类,美洲狮。它比现代非洲物种大25%,是有史以来最大的猫科动物之一。

There was a North American subspecies of jaguar, too. Known as the giant jaguar, it was significantly larger than its extant counterpart, and ranged as far north as Oregon. And there were American cheetahs! These belonged to a separate genus to the cheetah of today, being significantly larger, but probably behaviourally similar. In fact, they are likely the reason why the pronghorn antelope evolved to run at such breakneck speeds - none of its extant predators can keep up.

北美也有美洲虎的一个亚种。它被称为巨型美洲虎,比现存的同类要大得多,最远可以北上到俄勒冈州。还有美洲猎豹!它们属于今天的猎豹的一个单独的属,体型要大得多,但行为上可能相似。事实上,它们很可能是叉角羚进化成跑得如此快的原因——它现存的掠食者都赶不上。


So that covers the felines, but there are also some canines to consider. The most famous would of course be the dire wolf. Once considered to be a close relative of the grey wolf, it’s know considered a separate genus hailing from an American lineage - Aenocyon dirus.
Dire wolves were easily as large as the biggest grey wolves around today, making them one of the largest canid species.

以上,涵盖了猫科动物,但也要考虑一些犬科动物。最著名的当然是可怕的狼了。曾经被认为是灰狼的近亲,它被认为是美洲血统的一个单独的属——恐狼(Aenocyon dirus)。
恐狼很容易就能和今天最大的灰狼一样大,使它们成为最大的犬科动物物种之一。
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In the Pleistocene, grey wolves themselves were supersized. Found in the far northwest of North America (as well as much of Eurasia), the megafaunal wolf was a distinct eco-morph of the wolf species which was adapted for feeding on the much larger wildlife of the time.
It had a bulkier frx, was broader across the snout, and had powerful overdeveloped carnassial teeth. These adaptations allowed it to deliver a very strong bite.

在更新世,灰狼本身体型巨大。巨型狼发现于北美洲的遥远西北部(以及欧亚大陆的大部分地区),是一种独特的生态变种狼,适应了以当时更大的野生动物为食。
它有一副笨重的骨架,更宽的鼻子,和强大的、极度发达的、食肉的牙齿。这些适应性使它能够咬合力非常强。
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The third extinct species of dog in North America was Protocyon. It was a little smaller than a wolf, and its closest living relative is thought to be the strange South American bush dog, which I discuss in further detail in this answer. It likely hunted in packs, and bite marks show it preyed on giant armadillos.

在北美灭绝的第三种狗是原犬属。它比狼小一点,它现存的最近的亲戚被认为是奇怪的南美丛林狗,我将在这个回答中进一步详细讨论。它可能成群狩猎,咬痕表明它捕食巨型犰狳。
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Interestingly enough, the continent was also home to dholes. These reddish hunting dogs are not extinct, but are confined to Asia today. They once occupied much of Europe and North America too.
Then you had the bears. There were several different species of short-faced bears, which had blunt, truncated snouts designed for delivering bone-cracking bite force. The largest of all, Arctodus simus, was one of the biggest land-dwelling carnivorous mammals in history.

有趣的是,这片大陆也是狗的故乡。这些略带红色的猎犬并没有灭绝,但只分布在今天的亚洲。他们曾经占领了欧洲和北美的大部分地区。
然后是熊。有几种不同种类的短面熊,它们有钝的、截短的鼻子,用来提供咬碎骨头的咬合力。其中最大的熊齿兽是历史上最大的陆生食肉哺乳动物之一。
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Of course, there were predators not only on the land but also in the air. Birds of prey known as teratorns reigned over the skies in Pleistocene North America. They were some of the most massive birds ever to fly - one mysterious species, Aiolornis incredibilis, has an estimated wingspan of over five and a half metres!
Originally they were thought to be scavengers, like vultures, but now the consensus is that teratorns were largely ground-dwelling predators which snapped up small animals and swallowed them whole.

当然,不仅在陆地上,在空中也有掠食者。被称为teratorns(泰乐通鸟)的猛禽统治着更新世北美的天空。最初,人们认为它们是像秃鹫一样的食腐动物,但现在的共识是,泰乐通鸟主要是生活在地面的捕食者,它们会吃掉小动物,并把它们整个吞下去。


And they weren’t the only big birdies around. There were quite a few giant condors, as well as the huge Woodward’s eagle. It was at least as large as the largest living eagle, the harpy eagle, and its wingspan exceeded that of even the heaviest eagle of all time, New Zealand’s Haast’s eagle.

它们不是唯一的大型鸟类。这里有很多大秃鹰,还有巨大的伍德沃德鹰。它至少和现存最大的鹰——大雕一样大,它的翼展甚至超过了有史以来最重的鹰——新西兰的哈斯特鹰。

Even more unusual was Daggett’s eagle, which was actually a hawk. Its wings were quite short, and its legs very long, adapted for walking long distances. This means it probably lived a similar lifestyle to the charismatic secretarybird of Africa. It stood up to 90 cm tall.
So, all that covers mainland North America, but I haven’t yet touched on the Caribbean Islands. Wildlife-wise, these were a veritable different planet in the Pleistocene. The lower sea levels meant that most islands were much bigger, with more room to accommodate megafauna.

更不寻常的是达格特的鹰,它实际上是一种隼。它的翅膀很短,腿很长,适合长距离行走。这意味着它的生活方式可能和非洲魅力十足的蛇鹫相似。它高达90厘米。
以上,涵盖了北美大陆的物种,但我还没有谈到加勒比群岛。就野生动物而言,更新世时是一个完全不同的星球。较低的海平面意味着大多数岛屿要大得多,有更多的空间容纳巨型动物。


However, they were still islands, and many of the animals there which had migrated from the mainland experienced insular dwarfism.
The ground sloths, for example, were much smaller than the gargantuan species offshore. The largest Caribbean sloth weighed “only” 90 kilograms. Some of them may have even been partially arboreal. These sloths may actually be the reason that today’s Cuban crocodile has adaptations for hunting on land.

然而,它们仍然是岛屿,许多从大陆迁徙过来的动物都患有孤岛侏儒症。
例如,地懒比近海的巨型物种要小得多。最大的加勒比地/树懒“只有”90公斤重。其中一些甚至部分是树栖的。实际上,这些地懒可能是今天古巴鳄鱼适应陆地狩猎的原因。

In the Caribbean, there were also diverse radiations of monkeys and gigantic rodents called giant hutia. The largest one may have weighed up to 200 kg, or more than triple the weight of the biggest living rodent! Now that’s what I call a Rodent of Unusual Size. However, the most amazing thing about the Pleistocene Caribbean was not its mammals nor its crocodiles but its bird life. The feathered friends of these islands evolved flightlessness many times…
There was the giant flightless crane Grus cubensis, the flightless owl Ornimegalonyx, which was the largest owl ever to live (standing over a metre tall and weighing 30 kg):

在加勒比海,也有各种各样的猴子和巨型啮齿类动物,被称为巨型鼠。最大的一只可能重达200公斤,是现存最大啮齿动物重量的三倍多!



然而,更新世加勒比地区最令人惊奇的不是哺乳动物,也不是鳄鱼,而是鸟类。这些岛屿上有羽毛的朋友们多次进化出不能飞行的能力……
还有巨大的、不会飞的鹤Grus cubensis(古巴鹤),不会飞的猫头鹰Ornimegalonyx(未查到中文对等词汇),这是有史以来最大的猫头鹰(站起来超过一米高,体重30公斤):


There were also flightless ibises in Hawaii at the time, which had its own wacky birdlife, which I shall very quickly detail. I suppose you could consider it part of North America.
In addition to this ibis, Apteribis, there were a handful of species of moa-nalo, odd, goose-like ducks. Speaking of geese, there was a giant species aptly named the giant Hawaii goose:

最有趣的是不会飞的牙买加朱鹭。这种鸟的翅膀上长着重骨,用作棍棒状的战斗武器。
当时在夏威夷也有不会飞的朱鹭,它们有自己古怪的鸟类生活,我将很快详细介绍。我想你可以认为它是北美的一部分。除了这只朱鹭,还有Apteribis(异鹮属),还有一些moa-nalo(鸭亚科),一种奇怪的,像鹅一样的鸭子。说到鹅,有一种巨大的物种被命名为巨型夏威夷鹅:
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weirdest of all, the Kauai mole duck. I would sum this one up as a feathered platypus - it was flightless, probably blind and nocturnal, and it navigated its surroundings by touch and smell using its huge, flat beak. There were plenty of other extinct animals found in Hawaii from this time period, including a bat (one of only two known native Hawaiian land mammals), but none were as interesting as the birds described above.

最奇怪的是考艾岛的鼹鼠鸭。我会把这种带羽毛的鸭嘴兽总结为——它不会飞,可能是没有视力,昼伏夜出,用它巨大扁平的喙靠触觉和嗅觉来导航。
在这个时期,夏威夷还发现了许多其他灭绝的动物,包括蝙蝠(夏威夷仅有的两种本土陆地哺乳动物之一),但没有一种像上面描述的鸟类那样有趣。

So, that about covers the entire North American continent during the Pleistocene epoch. There are so many other Ice Age regions I'd love to talk about — the Pampas, Patagonia, Doggerland, the mammoth steppe, the green Sahara, East Africa, Madagascar, India, China, Japan, Indonesia, Sahul, New Zealand, Fiji, New Caledonia and more. But they'll have to wait.
Thank you very much for soldiering through this very long answer, I hope you got some enjoyment out of it, have a great day.

这大概覆盖了更新世时期的整个北美大陆。还有很多其他冰河时期的地区我想谈及——潘帕斯草原、巴塔哥尼亚、多格兰、猛犸象草原、郁郁葱葱的撒哈拉地区、东非、马达加斯加、印度、中国、日本、印度尼西亚、萨胡尔、新西兰、斐济、新喀里多尼亚等等。但它们不得不等等了。
非常感谢你能抽出时间阅读这篇长文,我希望你从中得到一些乐趣,祝你今天愉快。

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