Podicipedini is a tribe of waterbirds belonging to the family
Podicipedidae containing the genera ''
Aechmophorus'' and ''
Podiceps''. Members of this tribe of grebes are characterized based on the presence of nuptial plumes and downy young with a bare crown patch. They are more specialized for diving though the anatomy that enables them to do so makes them weaker to stand upright. Further they have much complex mating dance rituals. Based on these characteristics, other possible genera in the clade include ''
Poliocephalus'' and ''
Rollandia''.
Indeed a molecular phylogeny by Ogawa et al. (2015) using genetic data from 3 mitochondrial markers found ''Podiceps'' to be paraphyletic in respect to ''Rollandia'', as the latter genus is more closely related to several New World species of the former genus.
The inclusion of the
Neogene
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...
genera of ''
Pliolymbus'' and ''
Thiornis'' is based on their possible reclassification as junior synonyms as ''Podiceps''.
However there is uncertainty as different positions has been found for some members. One morphological study from Fjeldså (2004) found ''Rollandia'' to be the basalmost extant genus of grebe, with ''Thiornis'' being classified as a stem-grebe.
Another morphological study from Ksepka et al. (2013) found ''
Podilymbus'' to be the sister genus to ''Rollandia'', both more closer to ''
Aechmophorus'' and ''
Podiceps'', while ''Poliocephalus'' and ''Thiornis'' to be closer to ''
Tachybaptus''.
References
{{Taxonbar, from=Q33177309
Podicipediformes
Bird tribes