Weyl transformations and trace anomalies in N=1, D=4 supergravities

We identify the supersymmetric extension of Weyl transformations in various types of supergravities, the minimal, nonminimal and new minimal N=1 SUGRA in 4D, formulated in terms of superfields. Based also on previous results we conclude that there are only two types of trace anomalies in nonminimal and new minimal supergravities, which correspond to the two nontrivial cocycles of the minimal supergravity and, when reduced to component form, to the well-known squared Weyl density and Euler density. There are nevertheless in new minimal supergravity other nontrivial cocycles which, however, are mapped to zero in the minimal supergravity.