英语听力：恐龙是怎样炼成的—18

But it’s not completely finished. Paul and his team need Luis’ advice on a couple of issues.

There are several unknowns. And a complete tail has never been found. So on the older drawings that we have, there’s maybe 53 tailbones but the newer thinking is that there is close to 43. Paleontology, most of it is soft science. So these theories change with new evidence that is found.

One of the big questions about T-rex is what its surprisingly short arms were used for. They might have been used to hold on to prey or to push the body up from a sitting position. No one knows. And that’s partly because each arm is anchored to the body by the shoulder blade or scapular. And there is no easy way of telling exactly where that set.

With the scapular I’ve seen, they’ve gone up closer to the vertebra in the back bone. I’ve also seen where they were lowered almost to where belly is. There is a part of the front end of the scapular, the coccyx, and some people think they go together this much and some people think they go together this much. But that all has to do with how they, how everything hangs in the front end of this, and also how the hands were used. Those arms were just about the same size as we human arm.

The difficulty in placing the scapular on Tomas is compounded by the fact that the bones were distorted over the millions of years that they spent buried underground.

They were flattened. And they don’t really have the curvature that they must have had when the animal was alive before. It is really difficult to fit them on the sides of the ribcage. I guess that’s the nature of the beast. We are gonna have to find a compromise and we’ll live with it.

Back in L.A., there are two months to go before the exhibition opens. The 3 T-rexes are now installed.