  We investigate the collective behavior of a system of chaotic Rossler
oscillators indirectly coupled through a common environment that possesses its
own dynamics and which in turn is modulated by the interaction with the
oscillators. By varying the parameter representing the coupling strength
between the oscillators and the environment, we find two collective states
previously not reported in systems with environmental coupling: (i) nontrivial
collective behavior, characterized by a periodic evolution of macroscopic
variables coexisting with the local chaotic dynamics; and (ii) dynamical
clustering, consisting of the formation of differentiated subsets of
synchronized elements within the system. These states are relevant for many
physical and biological systems where interactions with a dynamical environment
are frequent.
