Abstract. We consider degenerate parabolic and damped hyperbolic equations involving an operator L, that is X-elliptic with respect to a family of locally Lipschitz continuous vector fields X = {X 1 , . . . , Xm}. The local wellposedness is established under subcritical growth restrictions on the nonlinearity f , which are determined by the geometry and functional setting naturally associated to the family of vector fields X. Assuming additionally that f is dissipative, the global existence of solutions follows, and we can characterize their longtime behavior using methods from the theory of infinite dimensional dynamical systems.