And Morganucodon still had this old-style jaw joint.

Morganucodon 仍然有这个老式的颚关节。

And, in mammals today, the two bones of that old-style jaw joint have since become part of our middle ear.

而且，在今天的哺乳动物中，旧式下颌关节的两块骨头已经成为我们中耳的一部分。

And while parrots' beaks are rigid, they have very flexible jaw joints, giving them a lot of control over how wide and how quickly they open their beaks.

虽然鹦鹉的喙是僵硬的，但其下颌关节十分灵活，这让它们可以很好地控制张开喙的宽度和速度。

The earliest ancestors of mammaliaforms had four bones in their jaws, and the jaw joint was formed by two bones called the articular and the quadrate.

哺乳类动物最早的祖先在颌骨中有四块骨头，颌关节由称为关节和方骨的两块骨头组成。

It also had a second jaw joint made up of the same two bones as the jaw joints of all living mammals - the dentary or mandible, and the squamosal.

它还有第二个下颌关节， 由与所有现存哺乳动物的下颌关节相同的两块骨头组成——齿骨或下颌骨，以及鳞骨。

And something really interesting was happening with its jaw joint, which is actually a key moment in the evolution of mammals, as weird as that may sound.

它的下颌关节发生了一些非常有趣的事情，这实际上是哺乳动物进化的关键时刻，尽管听起来很奇怪。

Now, I've had issues with my lower jaw for almost 20 years thanks to either a bad fall that damaged my jaw joint when I was young or some dental work in high school that misaligned my bite.

近 20 年来，我的下颌一直有问题，这要么是因为我年轻时的一次严重跌倒损伤了我的下颌关节，要么是因为高中时的一些牙科手术使我的咬合错位。