Taxonomic longevity in penguins (Aves, Spheniscidae)

ACOSTA HOSPITALECHE, C.

NEUES JAHRBUCH FUR GEOLOGIE UND PALAONTOLOGIE-ABHANDLUNGEN

E SCHWEIZERBARTSCHE VERLAGS

Año: 2006 vol. 7 p. 404 - 414

0077-7749

The current knowledge suggests that taxa of marine birds have distinctly  greater geological longevity compared to the continental birds. To recognize evolutionary and ecological patterns of Tertiary penguins, systematic, geographical and stratigraphical data for the different areas have been compiled, with emphasis on the South American fossil record. The main goals of the present study are: (1) To discuss the taxonomic longevities of penguins with respect to the parameters determined for South American continental birds, (2) To analyze the relationship between spatial and temporal distribution data for each taxon, and (3) To determine the time of establishment of the modern penguin fauna. The large number of taxonomic contributions, especially during the last few years, provides a systematic scheme with enough taxonomic consensus to allow the present study. The results indicate that: (1) The Spheniscidae do not conform to the evolutionary patterns that have been indicated for South American continental birds; their rate of morphological change was apparently much slower, resulting in species that were longer-lasting through time, (2) The species in the genera Paraptenodytes and Palaeospheniscus stand out because of their slow morphological evolutionary rate and for being more ecologically generalistic, whereas Eretiscus tonni and Arthrodytes andrewsi are interpreted as more rapidly morphologically evolving taxa, and more ecologically specialized forms, and (3) The current penguin fauna probably arose before the Early Pliocene.