Extremely metal-poor stars are uniquely informative on the nature of massive Population III stars .
Modulo a few elements that vary with stellar evolution , the present-day photospheric abundances observed in extremely metal-poor stars are representative of their natal gas cloud composition .
For this reason , the chemistry of extremely metal-poor stars closely reflects the nucleosynthetic yields of supernovae from massive Population III stars .
Here we collate detailed abundances of 53 extremely metal-poor stars from the literature and infer the masses of their Population III progenitors .
We fit a simple initial mass function to a subset of 29 of the inferred Population III star masses , and find that the mass distribution is well-represented by a power law IMF with exponent \alpha = 2.35 ^ { +0.29 } _ { -0.24 } .
The inferred maximum progenitor mass for supernovae from massive Population III stars is M _ { max } = 87 ^ { +13 } _ { -33 } M _ { \odot } , and we find no evidence in our sample for a contribution from stars with masses above \sim 120 M _ { \odot } .
The minimum mass is strongly consistent with the theoretical lower mass limit for Population III supernovae .
We conclude that the IMF for massive Population III stars is consistent with the initial mass function of present-day massive stars and there may well have formed stars much below the supernova mass limit that could have survived to the present day .