Being endothermic is a lot of work.

那就是成为内温动物要付出太多了。

And flying takes a lot of energy too, so being endothermic would have helped.

飞行也挺消耗能量，所以也促使它们成为了内温动物。

The hottest 20 percent of endothermic mammals keep their bodies higher than 37.9 C.

前 20% 体温最高的内温哺乳动物体温超过了 37.9 摄氏度。

Endothermic creatures are special because they create enough internal heat to keep their body temperature above their environment.

内温动物很特别，它们体内能产生足够的热量使它们的体温能保持在高于环境的温度。

And by the late Cretaceous, birds were fully endothermic.

到白垩纪晚期，鸟类完全吸热。

And since exothermic reactions produce heat, that heat tends to favor the reverse endothermic reactions.

由于热反应会产生热量， 因此热量往往有利于反向吸热反应。

Leatherbacks, though not exactly endothermic, can be considered Gigantothermic.

棱皮龟虽然不完全是吸热动物，但可以被认为是巨温动物。

So some dinosaurs appear to have endothermic traits, while others have signs of being ectothermic.

因此，一些恐龙似乎有吸热特性，而另一些有变温的迹象。

A much more interesting reaction involves 2 different ions of cobalt that reach equilibrium in an endothermic reaction.

一个更有趣的反应涉及两种不同的钴离子， 它们在吸热反应中达到平衡。

How did a group of animals completely reorganize its physiology to go from mesothermic to endothermic?

一群动物如何完全重组其生理机能，从温热状态转变为吸热状态？

We tend to think of endothermic and exothermic animals as two sides of a coin, as if you're one or the other.

我们喜欢把内温性和外温性看成硬币的两面，似乎你必须是两者之一。

Remember? So much work that many endothermic species spend most of their time eating just to feed this engine of heat and survive.

还记得吗？许多内温物种消耗了大量精力，花大部分时间吃东西，就为了给身体提供能活下去的热能。

In addition to the exothermic hand-warmers that we have out there, there are also endothermic chemical ice packs for treating injuries.

除了我们现有的发热暖手器外，还有用于治疗损伤的吸热化学冰袋。

Meaning that if they were not exactly endothermic, they would have been able to take advantage of many of the endothermic benefits.

这意着如果它们不是完全吸热的，它们就能利用许多吸热的好处。

However, more recent research suggests that dinosaurs were endothermic, having the ability to warm themselves with their metabolism, which made them less reliant on the sun.

然而，最近的研究表明， 恐龙是吸热动物，能够通过新陈代谢使自己暖和起来，这使得它们对太阳的依赖性降低。

So even though most animals today are either one or the other, dinosaurs were probably somewhere in between – some dinosaurs were more ectothermic, while others were more endothermic.

因此，尽管今天的大多数动物都是其中之一，恐龙可能介于两者之间 - 一些恐龙更变温性，而另一些更吸热性。

When we look through a thin section of dinosaur bone, the pattern of these osteons looks more like that found in endothermic animals rather than that found in ectothermic animals.

当我们透过一块薄薄的恐龙骨头观察时，这些骨元的模式看起来更像是在吸热动物中发现的，而不是在变温动物中发现的。

Of course, there is still a lot of variation in these patterns, but in general, the bone structure of dinosaurs implies that they were more likely to be endothermic, like birds and mammals.

当然，这些模式仍然有很多变化，但总的来说，恐龙的骨骼结构表明它们更可能是吸热动物，就像鸟类和哺乳动物一样。

It gets a bit complicated up in here, but basically the thing to keep in mind is that endothermic reactions, which consume heat, are favored if heat is added so higher temperatures tend to feed endothermic reactions.

这里有点复杂，但基本上要记住的是， 如果添加热量， 消耗热量的吸热反应会受到青睐， 因此较高的温度往往会促进吸热反应。