英语听力：2013-04-03 恐龙之战之极限生存 Extreme Survivors—7（在线收听） |
Male lions defend their cubs against rivals who see their offspring as future competition for food and mates. So it’s likely that an intelligent predator like T-Rex would do the same. Compared to prehistoric plant eaters, its cerebrum, the part of the brain associated with strategy, is huge. So is the cerebellum which controls muscle function. This is an animal that can plan and execute a devastating attack. It’s a behavior hardwired into the brain. If you are trying to increase your evolutionary advantage, the best thing you can do is get more offspring into the future generation. And one of the best ways you can do that is to take better care of the offspring that you produce.
Laying eggs nearly depletes the female. She needs nourishment to stay strong. And nourishment means meat. While she searches for her next meal, the male stays behind to guard the nest. Luckily, a Tyrannosaurus Rex on the hunt is guided by some of the keenest senses in the Cretaceous.
Its eyesight would actually have been very, very good.
The eyes of a T-Rex are huge, the size of cricketballs. A large retina collects more light and more visual information so they can clearly see prey from as far away as six kilometers.
Critically, both eyes face forwards and their line of sight overlaps, so each eye looks at the same object from a slightly different angle. That means T-Rex can experience the world in 3-D.
There’s very little in the environment of T-Rex that would escape its attention.
For the T-Rex hungry after months of growing her eggs, making a kill may mean the difference between life and death.
Ankylosaurus is a herbivore, but it’s built like a tank, covered in steel-like armor. |
| 原文地址：http://www.tingroom.com/lesson/yytltsfx/2013/245993.html |