听完了上一期的文章,大家有没有做好实地去落基山中走一走的准备,然后,会有什么样的发现在等着我们呢?值得期待~~ Daisy小编我可是充分准备了去落基山探宝的准备。闲话少说 :-) Let's Go!
But there is more to these rocks than fine acoustics. These rocks tell the story of how the Rocky Mountains were made. The story begins with a mystery. 8,000 feet high in the Colorado Rockies, 60 miles northwest of Boulder, all kinds of strange impressions are found in rocks scattered over the landscape.
We find more than 100 species of marine animals right here at this site. We find sharks, we find lobsters, crabs. We find beautiful fossil clams which are all over the place.
These fossils are crucial evidence of what existed here before the Rockies emerged.
We are sitting at about 8,000 feet in the middle of the Rocky Mountains. And so when these fossils were formed, this was below the level of the ocean. This was below sea level.
This area was covered by a vast inland sea. It existed for over 30 million years and stretched from Utah to Missouri and from the Gulf of Mexico to the Arctic Sea.
And at this very site, it would have been very warm, almost tropical. And so envision, maybe, a day on the beach in Florida, or something like that.
This warm climate attracted a unique type of creature that left behind large, round imprints in the rocks. These fossils would play an important part in the investigation.
This fossil here is a giant fossil ammonite, and this animal, this coiled shell right here, is a relative of modern day squids. So the closest marine relatives today are squids, nautiloids, octopuses things like that. And so in this big coiled shell here, the animal would have lived at this end as tentacles would have stretched out right here. And this animal is really quite remarkable. It is about the size of a truck tyre. And this is incredible because most ammonites aren't this big.
Nowhere else have scientists found a greater number of these prehistoric creatures than here. Miller has come up with a theory why so many of them came to this area.
We think this particular fossil here was a female ammonite. And we think that in part because male squids are smaller than female squids by a lot. So just looking around the fossil deposits here, we found a male ammonite, the small one here. So compare the size of this guy, there is a very big one here. And when we look across this landscape, we find mostly these big ammonites. And so we think that maybe all these females got together to spawn, and then died after they spawned.
小编有约:该大家发言啦!能告诉我,今天咱们最大的发现是什么?
A. prehistoric creatures B. particular fossil C. A theory
根据Daisy的三个线索你知道答案了吗?