Previous studies of structural instabilities in thin, nonwetting, liquid homopolymer films on substrates have focused on systems that dewet, forming patterns that reflect fluctuations in the local film thickness. These patterns range from discrete cylindrical holes throughout the surface of the film to bicontinuous "spinodallike" patterns. In this paper we show that a thin liquid film, a random copolymer, styrene-ran-acrylonitrile (SAN) comprised of 75% styrene and 25% acrylonitrile, of thickness h=12 nm becomes unstable and dewets silicon substrates, forming what we describe here as an intermediate morphology. During the early stage of dewetting, discrete noncylindrical, irregular, shaped holes appear spontaneously in the film. The number of holes, N, initially increase with time and the morphology of the late stage of growth, after 18 days, is characterized by a bicontinuous pattern, distinct from conventional spinodal dewetting patterns. The dynamics of pattern evolution of this intermediate morphology are discussed.