Podilymbus majusculus
Podilymbus majusculus is an extinct species of grebe recovered from the Piacenzian age of the United States.History
The specimens were collected in the summer of 1965 from Idaho, United States by Claude W. Hibbard and the species was named in 1967 by Bertram G. Murray. The species name "majusculus" is Latin for "somewhat larger or greater", referring to the larger size of the species compared to the related pied-billed grebe.Description
The holotype material is a complete tarsometatarsus. The tarsometatarsus is similar in characteristic to the pied-billed grebe, but being larger in size. Compared to the recently extinct Atitlán grebe, the tarsometatarsus of P. majusculus is slender in width and longer. Other material that Murray can confidently identified belonging to P. majusculus is the anterior portion of the sternum and a femur that is missing the proximal end. Both of these bone material are larger than any seen in pied-billed grebes. A complete ulna, a near complete femur, another femur with its distal portion, a proximal end of a femur, and a wornout but complete tarsometatarsus, and a possible complete scapula have been also assigned to the species. Tibiotarsii recovered from the similarly aged Rexroad Formation and the Saw Rock [Canyon Formation] of Kansas have been tentatively assigned to this species.Classification
Classified in the genus Podilymbus, P. majusculus is the oldest known of the Podilymbus species.Paleobiology
P. majusculus is known from the Glenns [Ferry Formation] which the formation dates from the Piacenzian age of the Pliocene epoch in Idaho, United States. The environment that P. majusculus lived in was a wetland where it cohabited with various waterbirds including Aechmophorus elasson, another Neogene grebe species. There is some size variation seen in the specimens where it is possible the larger ones are males and the smaller ones are females.