billr sends:
and notes:
Never mind that Brontosaurus didn’t actually exist (it was a conflation of a couple other species that did exist) I don’t know what the gag is. Or what the things on the rotisserie are.
The comments seem to confirm my guess, that the things on the spit are supposed to be Bronto-balls™. But I don’t get the joke either, beyond Beavis&Butthead-style humor?!
Comics I Don't Understand 
Rocky Mountain Oysters — long before there were any Rocky Mountains.
That seems in line with Dan Collins’ style. He regularly does strips where the joke is, “Ew, gross!” It’s not haute couture but it appeals to some people. I would have laughed when I was a boy.
I’m pretty sure the brontosaurus again used to exist, after some debate and taxonomical reshuffling. They now were a genus. I think it’s okay if our anachronistic Neanderthals aren’t concerned with what specific bronto they’re hunting.
Brontosaurus has been added back in, a similar sauropod was granted the name.
And yes, the joke is that they’re down to cooking the bronto balls, time to get a fresh one.
The Rocky Mountains well predate the advent of the great apes.
Glad that Dvandom got in there with the “well actually” before I could. Brontosaurus is indeed a real dinosaur again. Refreshing my memory from Wikipedia, scientists generally felt that Apatosaurus and Brontosaurus weren’t different enough dinosaurs to justify separate classifications, and since Apatosaurus was described first, it had naming priority. But in 2015, a paper analyzed the two with more modern techniques, including statistical analysis, and concluded they are in fact different enough to justify separate classifications. So Brontosaurus meat is back on the menu, boys!
(Although, as you might expect, this conclusion was not unanimously shared by paleontologists, and plenty continue to argue Brontosaurus is just a synonym for Apatosaurus.)