'Human bones are fragile things, but some are more fragile than others. The larger, denser bones of adults tend to be better preserved in the archaeological record than those of children, whose bones are more like a bird’s than an elephant’s: they are smaller, more porous and less mineralised, lack tensile and compressive strength, and may not be fully fused to their shafts (in the case of long bones). These skeletons are more vulnerable to both sedimentary pressure (when buried underground) and erosion from acidic soil and biodegrading organic matter. This is one of the main reasons why telling the stories of prehistoric children has been so difficult.'

https://aeon.co/essays/what-was-it-like-to-grow-up-in-the-last-ice-age