We derive properties of N-extended GR super Virasoro algebras. These includ
e adding central extensions, identification of all primary fields and the a
ction of the adjoint representation on its dual. The final result suggest i
dentification with the spectrum of fields in supergravity theories and supe
rstring/M-theory constructed from NSR N-extended supersymmetric GR Virasoro
algebras. (C) 2000 Elsevier Science B.V. All rights reserved.