We report for the first time the thermal study near the Sm-C-Sm-I critical point in free-standing thin films of 70.7 compound. The profiles of the Sm-C-Sm-I heat-capacity anomalies are found to exhibit an unexpected crossover behavior with film thickness in reduced dimensions. The data from two-layer films are not consistent with the predictions of two-dimensional melting theory. Our results also provide evidence in support of the recent theory proposed by Defontaines and Prost. Moreover, we confirm the existence of a surface hexatic Sm-L phase in 70.7 films of less than eight layers whose phase sequence is however dramatically different from that observed in the thicker films.