Whatever the bustard might be, he doesn’t have a 25’ wingspan or weigh 200 lbs. For that matter, the teratorn is more like a scaled up berkut and not a scaled up bustard, and the size limit for berkuts is in fact around 25 lbs. At that size berkuts begin to have problems taking off.
In fact, the closest living relatives to ancient Teratorns would be modern Condors, whose 10-foot wings support 33 lbs in flight.
Wing-load on a 25-foot wing Argentavis would be the same at around 165 lbs.
Argentavis are estimated circa 158 pounds.
