Kendrick makes sense to me - Cypress Hill were strongly associated with Lollapalooza (and Homerpalooza ), I think you need that hip-hop element.

Right you are! Just changed it.

True!! Good thinking. I guess they might have made mules with onagers.

At the end another academic cautions that whole they were probably riding horses, they could have been riding other animals and specifically mentions mules.

Mules are the offspring of a female horse and a male ass or donkey. So not only would horses already have to be domesticated to breed mules, they would also have to have access to donkeys - which they did not in the area surveyed during the time period being discussed. I don't see how it could be any other animal but a horse.

Edit: Had the sexes of the equines backwards

I mean, Detroit's right on the border.