 However, despite their size, Dinornis eggs were extremely thin, with "D. novaezealandiae's" eggshells being around 1.06 millimeters (0.04 inches) thick and "D. robustus' "eggshells being 1.4 millimeters (0.06 inches) thick.As such, "Dinornis" eggs have been estimated to be the 'most fragile of all avian eggs measured to date'.It is possible that such fragile eggs resulted in the male moa adapting to become smaller in size than the females to reduce the risk of crushing the eggs.