Taxonomic status of the Eocene penguins Orthopteryx gigas Wiman, 1905 and Ichtyopteryx gracilis Wiman, 1905 from Antarctica

ACOSTA HOSPITALECHE, C .; REGUERO, M.

ALCHERINGA

TAYLOR & FRANCIS LTD

Año: 2010 vol. 35 p. 1 - 5

0311-5518

Traditionally the systematics of the Seymour Island fossil penguins has been based on Wiman?s groups-categories defined by the robustness and size of isolated postcranial bones. However, the current understanding of fossil penguins proposes that new species be established when the specimens include at least a tarsometatarsus or in some cases a humerus. Accordingly, neither of the two species reviewed herein (Orthopteryx gigas  and Ichtyopteryx gracilis) are represented by remains sufficiently complete to validate a new taxon. Orthopteryx gigas is based on an isolated synsacrum lacking diagnostic characters. Ichtyopteryx gracilis is based on a tarsometatarsus but with insufficient preservation quality to justify discrimination of the species. For these reasons both Orthopteryx gigas  and Ichtyopteryx gracilis should be considered nomen dubia.