Capitalism began when Thag declared that he owns all the dinosaurs, and anyone who hunts a dinosaur must pay him 10 percent of the meat as a tribute, or else he will stab them with his spear.

First, pedantically, we did not share time with 'dinosaurs' in the sense you imply.

Secondly, pedantically, that kind of hunting was not the main source of calories for hunter-gatherers. It's more apt to imagine them as gatherers first and primarily.

Thirdly, and also pedantically, you are not describing the system of capitalism that I, and most educated people talk about when they use the word. That system has only been with us in the main for, generously, 250 years.

Critically, Thag and Grog both own the means of production for their spears and 'steaks' respectively. The necessary abstractions for capital accumulation, debt, and private ownership simply do not exist.