TED_Topic7：How we unearthed the spinosaurus

By Nizar Ibrahim

A 50-foot-long carnivore who hunted its prey in rivers 97 million years ago, the spinosaurus is a "dragon from deep time." Paleontologist Nizar Ibrahim and his crew found new fossils, hidden in cliffs of the Moroccan Sahara desert, that are helping us learn more about the first swimming dinosaur — who might also be the largest carnivorous dinosaur of all.

# Background about our speaker

Nizar Ibrahim scours（四处搜索、(费力地) 擦洗）Northern Africa for clues to what things were like there in the Cretaceous period（白垩纪）. A 2015 TED Fellow, he has spearheaded（带头；做先锋） the recent search for the semi-aquatic（半水生的） dinosaur spinosaurus（棘龙）.

# Why you should listen

Paleontologist（古生物学者） Nizar Ibrahim, a postdoc（博士后） at the University of Chicago, wanted to uncover the mystery of the spinosaurus, a bizarre, gigantic predatory dinosaur whose only known remains（残余；遗骸） were lost during World War II. After identifying a new skeleton at a dig in North Africa, Ibrahim made the landmark（adj. 有重大意义或影响的） conclusion that the spinosaurus may have been the largest carnivorous dinosaur to ever live. Its crocodile-like head, dense bones（密质骨）, short legs, and wide, paddle feet suggest it was a water dweller unlike any other. “The entire skeleton has water-loving river monster written all over it,” he says.

# 视频地址

https://www.ted.com/talks/nizar_ibrahim_how_we_unearthed_the_spinosaurus#

#Subtitles and Transcript

These dragons from deep time are incredible creatures. They're bizzarre, they're beautiful, and there's very little we know about them.

These thoughts were going through my head when I looked at the pages of my first dinosaur book. I was about five years old at the time, and I decided there and then that I would become a paleontologist. Paleontology allowed me to combine my love for animals with my desire to travel to far-flung corners of the world.

And now, a few years later, I've led several expeditions（(以探险等为目的的) 有组织的旅行，短程旅行） to the ultimate（极限的、终极的） far-flung（遥远的；广泛的；广布的） corner on this planet, the Sahara. I've worked in the Sahara because I've been on a quest to （寻找、探求）uncover new remains of a bizarre, giant predatory dinosaurcalled Spinosaurus.

A few bones of this animal have been found in the deserts of Egypt and were described about 100 years ago by a German paleontologist. Unfortunately, all his Spinosaurus bones were destroyed in World War II. So all we're left with are just a few drawings and notes.

From these drawings, we know that this creature, which lived about 100 million years ago, was very big, it had tall spines on its back, forming a magnificent sail, and it had long, slender jaws（口；狭口；咽喉）, a bit like a crocodile, with conical（圆锥的；圆锥形的） teeth,that may have been used to catch slippery（狡猾的） prey, like fish. But that was pretty much all we knew about this animal for the next 100 years.

My fieldwork（野外工作；现场工作；野战工事；实地调查） took me to the border region between Morocco（摩洛哥） and Algeria（. 阿尔及利亚）, a place called the Kem Kem. It's a difficult place to work in. You have to deal with sandstorms and snakes and scorpions（蝎子）, and it's very difficult to find good fossils there. But our hard work paid off. We discovered many incredible specimens. There's the largest dinosaur bone that had ever been found in this part of the Sahara. We found remains of giant predatory dinosaurs, medium-sized predatory dinosaurs, and seven or eight different kinds of crocodile-like hunters.

These fossils were deposited in a river system（河川系统）. The river system was also home to a giant, car-sized coelacanth（空棘鱼）, a monster sawfish（锯鲛）, and the skies over the river system were filled with pterosaurs（翼手龙）, flying reptiles（爬行动物）. It was a pretty dangerous place, not the kind of place where you'd want to travel to if you had a time machine.

So we're finding all these incredible fossils of animals that lived alongside Spinosaurus, but Spinosaurus itself proved to be very elusive（神出鬼没的）. We were just finding bits and pieces and I was hoping that we'd find a partial skeleton at some point.

Finally, very recently, we were able to track down（查出 找到 ） a dig site（考古挖掘场） where a local fossil hunter found several bones of Spinosaurus. We returned to the site, we collected more bones. And so after 100 years we finally had another partial skeleton of this bizarre creature. And we were able to reconstruct it.

We now know that Spinosaurus had a head a little bit like a crocodile, very different from other predatory dinosaurs,very different from the T. rex（霸王龙）. But the really interesting information came from the rest of the skeleton. We had long spines, the spines forming the big sail. We had leg bones, we had skull bones, we had paddle-shaped（形状如桨 ） feet, wide feet --again, very unusual, no other dinosaur has feet like this -- and we think they may have been used to walk on soft sediment（沉积；沉淀物）, or maybe for paddling（用桨划；在水中行进） in the water. We also looked at the fine microstructure of the bone, the inside structure of Spinosaurus bones, and it turns out that they're very dense and compact. Again, this is something we see in animals that spend a lot of time in the water, it's useful for buoyancy control（浮力调节，浮力控制） in the water.

We C.T.-scanned all of our bones and built a digital Spinosaurus skeleton. And when we looked at the digital skeleton,we realized that yes, this was a dinosaur unlike any other. It's bigger than a T. rex, and yes, the head has "fish-eating" written all over it, but really the entire skeleton has "water-loving" written all over it -- dense bone, paddle-like feet, and the hind limbs（后肢） are reduced in size, and again, this is something we see in animals that spend a substantial amount of time in the water.

So, as we fleshed out（跃然纸上、充实、具体化） our Spinosaurus -- I'm looking at muscle attachments（附着物） and wrapping our dinosaur in skin -- we realize that we're dealing with a river monster, a predatory dinosaur, bigger than T. rex, the ruler of this ancient river of giants, feeding on the many aquatic animals I showed you earlier on.

So that's really what makes this an incredible discovery. It's a dinosaur like no other. And some people told me, "Wow, this is a once-in-a-lifetime（一生仅有一次的 ） discovery. There are not many things left to discover in the world." Well, I think nothing could be further from the truth（远离真相 ）. I think the Sahara's still full of treasures, and when people tell me there are no places left to explore, I like to quote a famous dinosaur hunter, Roy Chapman Andrews, and he said, "Always, there has been an adventure just around the corner （在拐角处；即将来临）-- and the world is still full of corners." That was true many decades ago when Roy Chapman Andrews wrote these lines. And it is still true today.

Thank you

# Comments I like

What's the evolutionary advantage of the sail on the spinosaurus' back?

Things, including animals, are not "who." Only people are "who.' Everything else is "that." 。What happened to schools and teachers?