  For cross-diffusion systems possessing an entropy (i.e. a Lyapunov
functional)we study nonlocal versions and exhibit sufficient conditions to
ensure that thenonlocal version inherits the entropy structure. These nonlocal
systems can beunderstood as population models per se or as approximation of the
classical ones.With the preserved entropy, we can rigorously link the
approximating nonlocalversion to the classical local system. From a modelling
perspective this gives away to prove a derivation of the model and from a PDE
perspective this providesa regularisation scheme to prove the existence of
solutions. A guiding example isthe SKT model [22]. In this context we answer
positively the question raised byFontbona and M{\'e}l{\'e}ard [12] for the
derivation and thus complete the derivation.
