标签：Ice Age Oasisa 相关文章
These holes are the unmistakable hallmark of a violent death. Their shape suggest they were made by the teeth of a big cat, but which one? Today theres only one large cat in the region, the Florida panther. Though similar to the cougar at the western
探索与发现2012年
But how did one man and a spear produce the huge force behind this blow? The answer lies with small bits of ivory like this. They were once part of an atlatl, or spear thrower. An atlatl acts as a sort of catapult, magnifying the strength of a hunter
探索与发现2012年
By piecing together the evidence these creatures left behind, we can build a picture of this sub-tropical corner of the continent as it was 13,000 years ago. While most of North America was still in the grip of the Big Freeze, Florida was an ice age
探索与发现2012年
This is Florida, a taste of the tropical, one of the world's most popular holiday destinations. Here mankind's unquenchable desire to explore and colonise reaches astronomical proportions. Eight, seven, six, five, four, three, two, one. Ignition. Lif
探索与发现2012年
This creates steam in oasis and a profusion of life. Today, these warm springs are a refuge for one of Florida's most tropical inhabitants. The West Indian Manatee wasn't present during the last ice age, but returned here as the waters warmed up. Eve
探索与发现2012年
Meanwhile, the ground sloth, like the mastodons, must eat most of the day to fuel its huge bulk. This may be the ice age, but by midday, temperatures soar, drawing another predator to the spring to drinkthe notorious saber-toothed cat. Most creatures
探索与发现2013年
Today, there is a group of larger visitors here, too. A herd of mastodons led by the matriarch have just returned from their annual migration hundreds of miles to the north. Now the winter drought is over and the spring water has been topped up by re
探索与发现2013年
This triggered other dramatic changes. As sea levels dropped, so did the inland water tables. Florida's fresh water drained away through the porous limestone rock. Pools dried up and springs diminished. Florida was on the brink of drought. And animal
探索与发现2013年
Could it be that drastic water shortage was the reason for the mastodons' epic migrations? Another big piece of this puzzle lies far out to sea. This is the ocean floor. But this isn't rock sprouting out at the bottom. It's wood. It's the remains of
探索与发现2013年
Some of this ice age dung was found beneath the skull in the Aucilla. The dung contained plant remains that tell us what the mastodon was browsing on 13,000 years ago or morea mixture of trees and grasses. This suggests that ice age Florida was drier
探索与发现2013年
But despite their name, the mighty Everglades did not exist during the ice age. So what did pre-historic Florida look like? There is one place in northern Florida that has revealed more ice age secrets than almost anywhere else, the dark slow-moving
探索与发现2013年
They can grow more than two metres long and weigh as much as three men. But the giant tortoises of ice age North America were even larger. Florida does have tortoises today, but on a much smaller scale. This is the gopher tortoise. Tortoises are cold
探索与发现2013年
It's likely giant ground sloths used their claws in a similiar way to hook branches and pull them within reach. Like tree sloths, they were vegetarians and probably not fussy about what they ate, chewing their way through leaves, fruits, twigs and al
探索与发现2013年
During the last ice age, rapid swings in temperature occurred within decades or less, meaning populations of organisms had to adjust quickly to new environments or face extinction. 在最后一个冰河世纪中，温度在数十年甚至更短的时间
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By Alan Silverman Hollywood 02 April 2006 It's back to prehistoric times for a sequel to the 2002 computer-animated family film that featured a grumpy mammoth and his traveling companions: a quick-wit
2006年VOA标准英语（四月）
Global Warming Could Delay Next Ice Age The next ice age could be delayed by tens of thousands of years due to excessive amounts of heat-trapping carbon dioxide in the atmosphere, which disrupts Earths natural cycle of warming and cooling, according
VOA标准英语2012年(一月)
Ice Age Melt Offers Future Climate Clues University of Wisconsin geologist Anders Carlson studies ice sheet melt from land and ocean sediment cores. His study describes what prehistoric Earth was like in North America and Northern Europe some 140,000
VOA标准英语2012年(八月)
Greenhouse Gas Speeded Ice Age Melting A new study in the Journal Nature provides compelling evidence that carbon dioxide was a major driver of climate change at the end of the last Ice Age. That correlation supports the prevailing scientific view th
VOA标准英语2012年(四月)
In the heat of the day, hunters can afford to slow down and rest in the shade. Its one of the advantages of a high-protein diet. Llamas originated here in North America are the regular visitors to the spring. The strange-looking tapir is common too.
探索与发现2013年
Though very powerful, shes not a sprinter and she needs to get close to her prey before she strikes. This time shes run too soon and its a fruitless chase. Then her attention is diverted to a slower-moving target, slow but not defenseless. She backs
探索与发现2013年