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

We consider the supersymmetric extension of Weyl transform ations in various types of supergravities, the minimal, 20+20 and 16+16 nonmi nimal N=1 SUGRA in 4D, formulated in terms of superfields and study their local coho mology. Based also on previous results we conclude that there are only two types of trace anomalies in 20+20 and 16+16 nonminimal 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.