英语听力：自然百科 Ancient Sea Life in Utah 探秘古犹他州

 Perhaps at first glance, you wouldn’t expect to find evidence of marine 1 animals in the area of deserts and canyons 2 in southern Utah. But a team of paleontologists believe it’s the perfect spot. Led by National Geographic 3 grantee Barry AlBright, they are searching the remote sections of Grand Staircase--Escalante National Monument, for the fossilized remains 4 of plesiosaurus, a large marine reptile 5 that swam here 93 million years ago.

 
"I think one of the biggest questions people ask is why we’re looking for a large marine predatory reptile in southern Utah. You know we are not over a coast of California, or the, or the eastern coast, we are not even near an ocean. Ninety three million years ago the world was entirely 6 a different place."
 
During the age of the dinosaurs 7, this barren desert was covered by a vast inland sea. It stretched all the way from the Gulf 8 of Mexico to the Arctic Ocean, basically cutting what’s now America in two. This area in Utah was once the coastline of the shallow sea, something experts can tell by the exposed rock. They are particularly interested in a grey layer known as tropic shale 9, which holds fossils of ancient sea life. This area is so inaccessible 10 that the helicopter had to drop the team here with enough supplies to last several days.
 
"All right, here we go. Here is it.  Here is a fossil, not a plesiosaurus's , but we got a fossil here out, here is a nice oyster 11. Check that out. (Eonothem ) Yeah,Eonothem. Yeah."
 
Team member Alan Titus  has the ability to date layers of rock by examining fossilized invertebrates 12 in the shale called ammonites.
 
"These ammonites are great because we call them "guide fossils" and they do just that. They guide us to the right layers that we need to be looking at, and in fact, this one tells us that I’m in a layer that’s just a little below where we should be focusing our efforts to find plesiosaurus."
 
The team must hike for miles up and down ridges 13 and valleys, looking for exposed shale.
 
"Here we go again. Today is the day. The tropic shale doesn’t reveal its fossils readily, it’s not a highly fossil at first. And you can go literally 14 for days, I’ve spent days and weeks out here with a crew of six or seven or eight people. And we’ve walked the tropic shale eight, nine, ten hours a day and not found anything more than a couple of sharks’ teeth. So it’s not as if these plesiosaurs just laying around everywhere."
 
After searching for days over rugged 15 terrain 16, something catches the eye of one of the team members.
 
"What do you think? Oh, I think we got some bone. I think so too. Cow bone maybe. Tell you what, this looks... There is more. Oh, here is a fragment, there is a fragment, all over here. Ok, we’ve got, we’ve got a site here. Oh, wow, here is, here is a nice fragment, this stuff is just eroding 17 up."
 
And last, they have found the remains of an ancient plesiosaurus. And the search is on for bones and clues.
 
"Oh, hey, Maral, I got shark’s tooth, finally I got shark's tooth right on the surface, nice one, look at that, it's squalicorax, looks like carina, I think we've find a little zone here then we can spend some time and we've got bone fragments, we've got sharks’ teeth, this is really encouraging."
 
The team gathers enough fossilized bone fragments to determine that they’re from a small species or possibly a  Juvenile. Plesiosaurus were not dinosaurs, although they lived during the same time period. They were carnivorous reptiles 18 that thrived underwater.
 
"They had the upper part of the pedals actually. So just imagine: the shaft 19 of the limb bone coming down, broadening out in this way and also going from round to flat, again along, along the end of this bone would have been what are equivalent to our wrist bones and then beyond that extending out what have been what are equivalent to our finger bones, just like in a sea turtle today or a dolphin today. The finger bones have been elongated 20 and there’s many more than just the three finger bones in each of our fingers."
 
"There has to be another out here. Yes, I was beginning to believe it is belonging to here… Yes, that’s huge, that is huge. That is huge."
 
The discoveries by Albright and his team will help us better understand what life was like in our world some 93 million years ago, when dinosaurs ruled the earth and plesiosaurus swam in a vast inland sea.
 
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