Short Note: An ibis-like bird from the Upper La Meseta Formation (Late Eocene) of Seymour Island, Antarctica

Abstract

Ibises are a group of medium- to large-sized, mainly wading birds in the family Threskiornithidae (Aves: Ciconiiformes; see also discussion in Mayr 2002). They are known from all the continents except Antarctica, though one species breeds as far south as Tierra del Fuego (del Hoyoet al.1992, p. 499). The oldest fossil bones (including skull elements) attributed to ibises are those ofRhynchaeites messelensisWittich, 1898 from the Middle Eocene of Messel, Germany (Peters 1983, Mayr 2002). Another supposed member of this group is the Pondaung bird from the late Middle Eocene of Myanmar (formerly Burma) represented solely by an incomplete tibiotarsus (Stidhamet al.2005, fig. 2). The taxonomic position ofMinggangia changgouensisHou, 1982 from the Late Eocene of China (Hou 1982) was recently questioned by Stidhamet al.(2005, p. 183). Here, we present a partial bill from the Eocene La Meseta Formation (Seymour Island, Antarctica) which most closely resembles that of ibises.