Which name(s) should be used for Araucaria‐like fossil wood?—Results of a poll

Abstract

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.

Charcoalified logs as evidence of hypautochthonous/autochthonous wildfire events in a peat-forming environment from the Permian of southern Paraná Basin (Brazil)

“…Anatomical parameters of the wood assemblage are those of the fossil-genus Agathoxylon Hartig (Philippe and Bamford, 2008;Rößler et al, 2014), pointing to a predominantly monotypical association (Fig. 9).…”

First report of permineralised plants in the Stephanian of Arnao (Asturias, northwestern Spain)

“…1). Although scarce axial parenchyma is present in the Asturian specimens, the systematic value of its presence is equivocal and it is difficult to judge its absence in a fossil wood as was discussed by Rößler et al (2014). It is also important to note that most specimens described as Cordaixylon do not exceed 6 cm in diameter (Trivett, 1992;Hilton et al, 2009) and probably represent the anatomy of small plants.…”

Changes of wood anatomical characters of selected species of Araucaria- during artificial charring - implications for palaeontology

“…Agathoxylon has a long stratigraphic record, dating as far back as the Devonian, it is globally distributed, but wood assignable to this genus has been produced by a variety of extinct gymnosperm groups systematically not closely related to Araucariaceae (e.g. Dutra & Stranz 2003;Philippe 2011;Rößler et al 2014). From an anatomical point of view, most species traditionally assigned to Agathoxylon fall well within the xylological variability of one or two modern species of the Araucariaceae (e.g.…”