英语听力：完美捕食—13

Picture a living plane, and that gives you a sense of what Quetzalcoatlus would look like in life.

And this is an animal that probably accelerates over 2.5G’s just on takeoff.

Just beyond our comprehension.

A Quetzalcoatlus is 10 times the weight of the largest flying bird today. Yet this airborne reptile doesn’t rely on feathers. Its wings are made of skin. Almost half of that wing is supported by an extended finger bone, a finger 2.5 meters long. A second bone lines the front of the wing, forming a leading edge, similar to an aircraft.

This aerodynamic design allows for near-perfect control on takeoff and landing. But for this flying monster, getting off the ground is the hardest task.

Big pterosaur like Quetzalcoatlus giraffe height on all fours, and it’s got to get up into the air. How is it gonna do that?

And that’s made it more difficult living on the plains of Texas.

Flat ground, no hills, no cliffs, no special conditions, nothing to help it at all except its muscles. It could still take off from a standstill without any running required.

The secret to how this Goliath takes off can be seen in a creature 1,000 times smaller, the vampire bat.

They have to spring up into the air. They have to do essentially a super push-up with their powerful forelimbs, the strongest limbs they have, get up high enough so that they can get their wings to flap and get off the ground.

A Quetzalcoatlus takes off in the same way, using all four limbs to suddenly leap up into the air. Its powerful arm muscles are composed of 80% fast-twitch fiber, a third more than humans. This specialized muscle tissue is capable of delivering rapid bursts of energy. This energy is needed to propel this creature weighing as much as a grizzly bear, from a dead stop to a launch speed of 50 kilometers…