The holotype (
UMMP 29079) is a complete left
tarsometatarsus, which is comparable in size to tarsometatarsi of the black-necked grebe and of the females of the
horned grebe (
P. auritus). It differs from them by its internal
condyle is not internally flared, and the head is small relative to the length of the bone. Further when viewed at the medial perspective, the tarsometatarsus of
P. discors is not as long or it is directed so far anteriorly as seen in other species of the genus. Additional material has been found in Idaho which represent a complete
femur (UMMP 52423), an almost complete
carpometacarpus (UMMP 49653), three
coracoids (UMMP 49590, UMMP 52277, and UMMP 52585), two
scapulae (UMMP 45289 and UMMP 49589) and two distal end fragments of two
tibiotarsi (UMMP 52432 and 52448). They are all similar to those of the same bone elements in the black-necked grebe with some overlap, though the bones are more slender in form by comparison. ==Paleobiology==