Michael Goldfarb has more. This seems to explain those child-bones:
There was a children’s cemetery unearthed while constructing a Combat Outpost (COP) in the farm land south of Baghdad International Airport. It was not a mass grave. It was not the result of some inhumane genocide. It was an unmarked cometary where the locals had buried children some years back. There are many such unmarked cemeteries in and around Baghdad. The remains unearthed that day were transported to another location and reburied.
The quoted soldier goes on to doubt that wearing a piece of skull under a helmet, as a private depicted in “Shock Troops” is supposed to have done, is even possible.