It is very fast, be very careful when you fly on spawns, minimum needs for ptera so it can outrun it is ~500 stamina and 170% speed, if your ptera is 180% or above don’t be scared, also it can attack you while you ride something, you should fly lover to the ground so you can use terrain or use paracers to lure rhynio on them, don’t EVER try to kill them with ptera, it’s literally impossible in any way imaginable, use strong dinos with much attack, lure them on you and go closer to them until they’ll attack you in melee and then you can easily kill it. Thanks for reading, dear player, if you’re newbie or encounter them first time, use this.