We report heat capacity measurements of the pnictide materials SmFeAsO 1-x F x, NdFeAsO, LaFeAsO 1-x F x and LiFeAs. For SmFeAsO 1-x F x, with x close to 0.1, we use 3 He measurements to demonstrate a transfer of entropy from the peak at T N to a previously unidentified∼ 2 K feature, which grows with increasing doping. Our results on the Sm samples are compared with a similarly doped La sample to elucidate the crystal field levels of the Sm 3+ ion at 0, 20 and 45 meV, which lead to a Schottky-like anomaly, and also show that there is a significant increase in the Sommerfeld coefficient γ when La is replaced by Sm or Nd. The lattice contribution to the heat capacity of the superconducting oxypnictides is found to vary negligibly with chemical substitution. We also present a heat capacity measurement of LiFeAs showing the feature at T c, which is significantly rounded and much smaller than the BCS value.