Tertiary palynology: Beaupreaidites and new Conospermeae (Proteoideae) affiliates

Abstract

Late Eocene proteaceous pollen assemblages of southern Australia containnumerous specimens of Conospermeae affiliation. As many of these aremorphologically confusing or nondescript, they have often been overlooked orgrouped within other fossil pollen species. In the western Eucla and MurrayBasins these fossil pollen types fall into two major categories: small speciesconventionally referred to unrelated New Zealand fossil taxa, and thoseincluded in Beaupreaidites elegansiformis Cookson 1950or Beaupreaidites spp. Integrated microscopy of singlefossil grains and a thorough investigation of extant Conospermeae pollen typesaided an investigation of the morphology and affiliations of these problematicgroups. Beaupreaidites elegansiformis was originallyillustrated by three dissimilar specimens, each from a different locality. Ofthese, two can be aligned with Beauprea Brongn. & Gris., and the other, the former lectotype, is an extinct form unrelated toBeauprea. The diagnosis ofBeaupreaidites Cookson emend. Martin is amplified;B. elegansiformis is emended and its lectotypesuperseded; B. orbiculatus Dettmann & Jarzen 1988 istransferred to Proteacidites; and five new species aredescribed (Beaupreaidites diversiformis,Proteacidites bireticulatus,P. carobelindiae, P. cirritulus,and P. marginatus).Proteacidites cirritulus can be positively aligned withpollen of the sclerophyllous genus Petrophile R.Br., inparticular with species now endemic to eastern Australia. The remainingProteacidites species, previously assigned toBeaupreaidites, were likely to have been shed by extinctproteaceous taxa closely allied to Petrophile. Therelative abundance of Petrophile-like pollen in thepalynofloras of the western Eucla and Murray Basins implies the presence ofsclerophyll communities akin to heath, woodland, and/or dry sclerophyllforests in coastal southern Australia during the Late Eocene. Fossilproteaceous genera are reviewed. The species referred here toProteacidites cannot be accommodated within any singlegenus as described in a recent revision of fossil proteaceous genera. Therehas long been quiet dissent among Australian Tertiary palynologists withrespect to revisions of fossil proteaceous genera and their subsequentinterpretation. Consensus, rather than individual determination and conflict,is overdue.