The redwoods are now basically a no fly zone, I lost a quetz, and a pter to these bastards. They jump out of the tree, rip you off your mount, and then pin you and your mastercraft armor to the ground and murder you.
Thylacoleo are capable of pinning down flyers in mid-flight (anything but the Quetz and Wyvern, I believe), other Thylacoleo, and even Therizinos. You can also jump from object to object by holding down the jump button while pouncing from a tree or cliff (have to hit it at the right angle, however). Upvote to inform others!