Late Eocene penguins from West Antarctica: systematics and biostratigraphy

Abstract

Penguins are by far the most dominant group of marine vertebrates in the Eocene La Meseta Formation (Seymour Island, Antarctica). We analysed the penguin fauna recovered there from both a systematic and a biostratigraphic point of view. We have added two new species (Tonniornis mesetaensis and T. minimum) and have defined a biostratigraphic unit, the Anthropornis nordenskjoeldi Biozone. This interval of strata, easily distinguishable by the numerous occurrence of penguin bones and the phosphatic brachiopod Lingula, is located nearly 30–35 m below the top of the 145 m-thick Submeseta Allomember. The highest morphological and taxonomic penguin diversity living sympatrically (organisms that live simultaneously in the same place), including giant and tiny species, is documented in this interval. Fossil penguins bones studied in this paper, recovered from rocks interpreted as shallow-marine deposits, accumulated between 34.2 and 36.13 Ma (late Late Eocene).

The Basal Penguin (Aves: Sphenisciformes) Perudyptes devriesi and a Phylogenetic Evaluation of the Penguin Fossil Record

“…Jadwiszczak (2006a: 7) indicated the IB/P/B collections include ''more than a thousand almost exclusively isolated bones.'' Tambussi et al (2006) noted that of .2000 Antarctic penguin elements curated in the MLP collections, only one partial skeleton is articulated. This presumably refers to the single incomplete specimen of Palaeeudyptes gunnari described by Accosta Hospitaleche and Reguero (in press).…”

Short Note: An intriguing penguin bone from the Late Eocene of Seymour Island, Antarctic Peninsula

“…In my opinion, however, it would not be advisable to erect a new taxon on such fragmentary material (cf. the case of specimen IB/P/B-0279b in Myrcha et al 2002, p. 34 Myrcha et al (2002), Jadwiszczak (2006a) and Tambussi et al (2006;but see Jadwiszczak 2006b) indicated the probable existence of more than five small-sized (see Jadwiszczak 2001) Eocene species. The tarsometatarsus presented here firmly confirms that conviction.…”

New crania from Seymour Island (Antarctica) shed light on anatomy of Eocene penguins

“…Most of the known remains are non−articulated bones and a vast majority of holotypes of penguin species from Antarctica are either tarsometatarsi (Myrcha et al 2002;Jadwiszczak 2006;Tambussi et al 2006) or humeri (Tambussi and Acosta Hospi− taleche 2007). Unfortunately, no cranium has been unequivocally assigned to any known Antarctic species.…”