@GeneralVan: Well they do have futuristic cities with anti gravity tech and dinosaurs, so it wouldn't surprise me.
@CosmicKnight75: Vegeta concentrated his energy on Cell, but that's a whole another topic. The light sphere of Nappa's attack is well over 100 thousand feet, making it a large country level blast in real life at least. The cities could also be way bigger then ours for all we know. Either way the city level statements and the scan don't match up.