- Where did it come from?
- I'm not sure. But I rather think it came from the Middle Cretaceous era. It wasn't here a moment ago.

11 seconds sound clip from the X Minus 1 - A Gun for Dinosaur by L. Sprague de Camp classic radio drama series.

You can hear this line at 00:26:27 in the radio play.

Quote context

[...]

- Reggie, are you all right?

- I seem to be.

- What happened?

- The time chamber. It's back. We'd better get it open.

(HATCH UNLOCKED AND OPENED)

(GASPS IN HORROR)

- Good Lord, look at that. Ghastly, isn't it?

- Where did it come from?

- I'm not sure. But I rather think it came from the Middle Cretaceous era. It wasn't here a moment ago.

- Ghastly mess. Looks as if every bone was pulverized and every blood vessel burst. I dare say.

- But that's his gun all right. It's James... there's no doubt of it.

- So, that's the story. Of course, I don't understand the mathematics, but the idea's rather easy to grasp.

- Nobody had shot us when we first emerged on the twenty-fourth of April, eighty-five million B.C., so, of course, that couldn't be changed.

[...]