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聞く/Video/MinuteEarth/Could This Thing *Really* Fly?

Could This Thing *Really* Fly?

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0:00This video is brought to you by FarmKind.  More about them at the end of the video.
0:05The Quetzalcoatlus – one of the  largest pterosaurs that ever lived
0:08– was able to… fly?!
0:11That doesn’t sound right.
0:13I mean, look at this thing –  it’s the size of a giraffe!
0:17However, giant pterosaurs’ ability to fly is  
0:20really well-established in  the scientific community.
0:23So how on Earth did this giant manage to fly?
0:28Hi, I’m Ever and this is MinuteEarth.
0:32Thanks to the fossil record,  
0:33we know that pterosaurs had wings with  elongated hand bones, just like every  
0:38other flying vertebrate. But simply having  wings doesn’t mean you can actually fly.
0:43If you’re too heavy for the size of those wings  – or if you can't flap them fast enough – you’ll  
0:49never get anywhere. And compared to the biggest  flying creatures alive today – the Kori bustard,  
0:55or the wandering albatross,  or even the Andean condor,  
0:58depending on how you measure it – the  Quetzalcoatlus was way, WAY bigger.
1:03But, despite this giant pterosaur’s wingspan,  
1:06scientists estimate that it was  only about as heavy as a large pig.
1:11Now with the wing-to-mass  ratio looking more decent,  
1:14giant pterosaurs still needed to  be strong enough to flap them.
1:18And while wing muscles themselves  aren’t preserved in the fossil record,  
1:22we know pterosaurs had huge bumps in their  forelimb bones and highly modified breastbones,  
1:28with ample attachment space for powerful chest  muscles – just like modern flying birds do.
1:34So it’s reasonable to believe their  wing muscles were pretty brawny.
1:38On top of that, pterosaurs had  mostly hollow bones that increased  
1:43the volume of their respiratory system  – again, just like modern flying birds –
1:48which allowed them to deliver tons of  oxygen to all those flight muscles!
1:53All this likely helped a Quetzalcoatlus’s  big body stay aloft once it was in the air.
1:59But getting into the air in the first place is the  hardest and most energy-intensive part of flight.
2:05Flying birds use their strong leg muscles  to launch themselves into the air;
2:10that’s why the bigger a bird is, the larger  and more powerful its legs tend to be.
2:16Giant pterosaurs were so huge that, in  order to jump into the air like birds,  
2:21they would have needed truly gigantic legs that  would have made them definitely too heavy to fly.
2:27So they solved the whole launching  problem in a different way:
2:31they used their powerful wings for the  dual purpose of taking off and flapping.
2:37And this strategy is so efficient, that  bats independently evolved it as well.
2:43By the way, I think that this is my favorite  fact about giant pterosaurs –and bats, of course.
2:48Once you look at all the evidence and the facts,  
2:50it makes perfect sense that these  giant pterosaurs could truly soar.
2:55They might look too big and wonky,  
2:58but the Quetzalcoatlus was about as  close as we’ve ever come to a flying pig.
3:04Pigs these days, of course, rarely fly.
3:08And – sorry to be a downer, especially after  that uplifting video - but in a lot of places,  
3:13the conditions they’re kept in are heartbreaking.
3:16As someone who loves animals, I hate  to see any animal suffering so much.
3:20That’s why we want to help make a genuine  positive change with today’s sponsor, FarmKind.
3:27FarmKind helps improve the lives of  animals by recommending expert-reviewed,  
3:31top charities whose work  really makes a big difference.
3:34Like Sinergia Animal, which  is helping end the inhumane  
3:38practice of keeping breeding  pigs confined in tiny crates.
3:42FarmKind never takes a cut of your donation;  it all goes to the charities helping animals.
3:47If you sign up for just $15 bucks a  month, that’s just 50 cents a day,  
3:53you'll save 350 animals from  unnecessary suffering in your  
3:57first year. Use the code MinuteEarth  for a 50% boost on monthly donations.
4:04If even a fraction of this community  did that, we'd transform the lives  
4:08of hundreds of thousands of animals. Check out  the description for more info. Thanks FarmKind.