  We study entanglement entropy in two-dimensional conformal field theories
with a gravitational anomaly. In theories with gravity duals, this anomaly is
holographically represented by a gravitational Chern-Simons term in the bulk
action. We show that the anomaly broadens the Ryu-Takayanagi minimal worldline
into a ribbon, and that the anomalous contribution to the CFT entanglement
entropy is given by the twist in this ribbon. The entanglement functional may
also be interpreted as the worldline action for a spinning particle -- that is,
an anyon -- in three-dimensional curved spacetime. We demonstrate that the
minimization of this action results in the Mathisson-Papapetrou-Dixon equations
of motion for a spinning particle in three dimensions. We work out several
simple examples and demonstrate agreement with CFT calculations.
