maybe it was the other way round
after all, according to Asimov the cleverest carnivorous dinosaurs had ray guns to hunt .. so who knows how advanced the mammoths were .. maybe they had Imperial star-destroyers? Those trunks are good substitutes for hands ;)
(sorry, couldn't resist it - interesting piece though, but rather preliminary I thought, without other evidence to correlate .. unless I'm ignorant of the other evidence)