英语听力：完美捕食—8

Sauroposeidon towers over Deinonychus. In fact, its mammoth size is its primary defense. But this giant begins life very small.

For Deinonychus, Sauroposeiden would be a great meal, at least the juveniles, because there would’ve been lots of them and because they would’ve been effectively defenseless.

When Sauroposeidon reaches full size at around 25 years old, nothing can compete. But this Goliath starts out about the size of a house cat. When these eggs hatch, the young grow fast, but not fast enough. They won’t even reach a ton in weight for at least three years, giving the raptor Dinosaurs plenty of time to attack.

There’s good evidence that Deinonychus killed animals that weighed 10 times as much as it.

And 10 times Deinonychus’ weight in raw meat is a very big meal.

They could probably feast for a while on, say, a three-year-old Sauroposeidon, an animal the size of a hippo.

Bringing down an animal 10 times your size takes more than just brains. It requires highly advanced senses.

We can tell that it had a good sense of vision, good hearing, and a pretty good sense of smell.

In fact, like few carnivores of its day, Deinonychus has a sense of smell so acute, it can track prey in the dead of night.

Inside the snout are two nasal passages. Like an air filter, sheets of sensory tissue are folded to maximize surface area. This tissue contains millions of chemoreceptors, nerves that capture odor molecules. So Deinonychus can sniff out prey from miles away.

The sense of smell in Deinonychus could alert…