Swooping Pteranodon's triggered ability targets only the creature an opponent controls. You choose the target land (where the poor creature is going to drop) as the delayed triggered ability triggers at the beginning of the next end step.
Flying, haste
Whenever this creature or another Dinosaur you control with flying enters, gain control of target creature an opponent controls until end of turn. Untap that creature. It gains flying and haste until end of turn. At the beginning of the next end step, target land deals 3 damage to that creature.
