To tame an argent you make his torpor rise most of the way then you kill yourself or a dino you can pull then you wait for it to eat the carcass once he eats it you ko it IMIDEATLY while the healing ability is in then once it is ko the food will drop half to all the way in less than 6 seconds ...90% tame with 145
An argentavis can't fit through a ceiling with one tile missing, but a pteranadon or lymantria can. Build a trap with one corner ceiling missing, aggro the argentavis, fly in one side and out the missing ceiling tile, and land. Dismount, run around, and close the entry door. Tame safely at your leisure.