When, Where And Why?

In Poul Anderson's "Wildcat," the opening paragraph has three sentences:

in the first, it rains in a swamp;
in the second, the viewpoint character sees a derrick and a floodlight;
in the third, he hears a brontosaur.

So where is he? In the past, in the Lost World or on another planet?

The second paragraph establishes only that he is on a dock and that it is still raining. In the third and fourth paragraphs, he evades, and shoots at, an attacking plesiosaur. Half way down the second page, Herries' altercation with the guards, who should have been more vigilant, establishes that he and they are a hundred million years in the past.

So why is this story in Conquests, a collection on the theme of human warfare? All will be revealed but that may be the limit of my blogging for today!

(Meanwhile, still among Wellsian themes, we have moved from space travel to time travel.)