Lancel's terrific book on Carthage does talk about the child sacrifices. Excavations have not confirmed the reality of the collective sacrifices mentioned by Diodorus, but it does show that in the earliest times the "sacrifices" were either newborn or stillborn babies and in the fourth century deposits they are largely of children aged one to three, and one out of three urns would contain remains of two or more children. When you notice at certain periods that animals are "substituted" in the burial urns it does seem to point more towards the possibility that these were indeed sacrifices instead of just burials. Lancel seems to me to doubt that they were just burials of infants in a time of high infant mortality rates - the children aged two to four that were common in some burials seems to indicate to him that they were sacrifices instead of just burials (the slightly older ages being outside the ranges where the highest mortality rates occur). The fact that animals' remains are found in the same urns with those older children would seem to point their sacrifices and not just burial. He does say firmly that evidence "in its present state does not permit a categorical denial of the reality of Carthaginian human sacrifice."