ABsTRACT. We present new data on the paleoichthyology, paleobotany and radiometric results of the Loreto Formation in the Brunswick

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Araucarioxylon Kraus is a widely known fossil-genus generally applied to woods similar to that of the extant Araucariaceae. However, since 1905, several researchers have pointed out that this name is an illegitimate junior nomenclatural synonym. At least four generic names are in current use for fossil wood of this type: Agathoxylon Hartig, Araucarioxylon, Dadoxylon Endl. and Dammaroxylon J.Schultze-Motel. This problem of inconsistent nomenclatural application is compounded by the fact that woods of this type represent a wide range of plants including basal pteridosperms, cordaitaleans, glossopterids, primitive conifers, and araucarian conifers, with a fossil record that extends from the Devonian to Holocene. Conservation of Araucarioxylon has been repeatedly suggested but never officially proposed. Since general use is a strong argument for conservation, a poll was conducted amongst fossil wood anatomists in order to canvass current and preferred usage. It was found that the community is divided, with about one-fifth recommending retention of the well-known Araucarioxylon, whereas the majority of others advocated use of the legitimate Agathoxylon. The arguments of the various colleagues who answered the poll are synthesized and discussed. There is clearly little support for conservation of Araucarioxylon. A secondary aspect of the poll tackled the issue as to whether Araucaria-like fossil woods should be either gathered into a unique fossil-genus, or whether two fossil-genera should be recognized, based on the respective presence or absence of axial parenchyma. A majority of colleagues favoured having one fossil-genus only. Agathoxylon can be used legitimately and appears to be the most appropriate name for such woods. However, its original diagnosis must be expanded if those woods lacking axial parenchyma are to be included.

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This study presents the first record of Eocene birds from the western margin of southernmost South America. Three localities in Magallanes, southern Chile, have yielded a total of eleven bird remains, including Sphenisciformes (penguins) and one record tentatively assigned to cf. Ardeidae (egrets). Two different groups of penguins have been recognized from these localities. The first group is similar in size to the smallest taxa previously described from Seymour Island, Marambiornis Myrcha et al., 2002, Mesetaornis Myrcha et al., 2002, and Delphinornis Wiman, 1905. The second recognized group is similar in size to the biggest taxa from Seymour Island; based on the available remains, we recognize the genus Palaeeudyptes Huxley, 1859, one of the most widespread penguin genera in the Southern Hemisphere during the Eocene. The stratigraphic context of the localities indicates a certain level of correlation with the geological units described on Seymour Island. The newly studied materials cast more light on the paleobiogeography of the group, extending the known ranges to the South American continent. In addition to the newly discovered birds, the presence of several taxa of elasmobranchs previously recovered exclusively from Eocene beds in the Southern Hemisphere help to clarify the age of the studied localities, widely discussed during the last decades. This paper verifies the presence of extensive Eocene sedimentary successions with fossil vertebrates along the western margin of southern South America, contrary to the previous assumption that such a record is lacking in Chile.