absent in Archaeopteryx, [25];
absent in Hesperornithes, [25], [26];
absent in Ratitae, [25], [26];
absent in Tinamidae, [25], [26], [182];
occasionally found in Apteryx, [26] n.;
occasionally found in Struthio, [26] n.
Pyranga, [575]
Pyrenestes, [577]
Pyriglena, [489]