Fock representations of non-centrally extended super-diffeomorphism algebras

A class of Fock representations of non-central extensions of the super-diffeomorphism algebra in (N+1|M) dimensions is constructed, by superization of the paper [physics/9705040]. The representations act on trajectories in (N|M)-dimensional superspace, the extra dimension being the parameter along the trajectory. The restrictions to various subalgebras are considered. In particular, the centrally extended superconformal algebra is obtained by restriction to the contact superalgebra K(1|1). This shows that one of the basic assumptions in superstring theory (the distinguished nature of the superconformal algebra) is incorrect.