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Suggested evolutionary lineages within Conospermeae based on pollen morphology. (A) The tectate-perforate genera: Stirlingia Endl., Conospermum Sm., and Synaphea R.Br. (B) Reticulate genera and those with stranded tectal features: Petrophile R.Br., Isopogon R.Br. ex Knight, Agastachys R.Br., Symphionema R.Br., and Aulax P.J.Bergius of the Proteoideae tribe Proteeae. Numbers shown at the right denote haploid chromosome numbers as per Ramsay (1963) and Johnson and Briggs (1963, 1975); boxed genera are members of Conospermeae within the same subtribe; B, living genera indicated by closed squares; G, postulated stages; ……, possible pathways.
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Pollen morphological trends in modern taxa, the fossil pollen record, andcomparative palynology can be useful aids to taxonomy and indicators ofevolutionary lineages. In Conospermeae, each species and genus has a distinctpollen morphology character set, although individual characters may not betaxon-specific. Aperture form in Conospermeae may be co...
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Citations
... Unpublished reports by bona fide palynologists available on the internet were accepted along with the usual published sources. We sometimes checked the identification of images provided with the papers against our own knowledge (Milne and Martin, 1998;Lamont et al., 2023) but usually did not cross-check identifications based on well-recognized form genera or identifications by palynologists considered experts on the Proteaceae. Note that our focus was on whether the grains could be assigned to Proteaceae or not. ...
... Therefore, pollen loads from each foraging insect were classified as one of the following: no pollen (<25 grains), pure loads (>25 grains of host flower only), mixed load (>25 grains of host flower + >25 grains of at least one other coblooming species), and alien load (>25 grains of other species but no grains of the host flower). While pollen grains of Symphionema montanum and Isopogon anemonifolius show morphological similarities (Milne & Martin, 1998), they were segregated under 20× light microscopy by comparing relative sizes (big. vs little), exine patterns, and sculpturing of operculate wall pores. ...
... List of spores and pollen recorded from the Foulden Maar diatomite including those taxa previously identified by Raine in Bannister et al. (2005). Botanical affinities are based on Anzotegui and Acevedo (1995), Dettmann and Jarzen (2000), Macphail (1999), Macphail and Cantrill (2006), Macphail and Stone (2004), Macphail et al. (1995), Mautino and Anzótegui (2000), Milne (1998), Milne and Martin (1998), Pocknall (1990), Raine (1998) and Raine et al. (2008Raine et al. ( , 2011 (continued on next page) representing autumn/winter conditions . It was expected, therefore, that there would be a difference in pollen content between the dark and the light layers. ...
... Finally, although we conclude from the above discussion that it is not possible to determine modern affinities of the fossils with any confidence, we note that pollen grains morphologically consistent with those of certain Australian sclerophyllous Proteoideae (e.g. Dettmann and Jarzen 1998;Milne 1998;Milne and Martin 1998) are diverse and locally abundant in the Gore Lignite Measures (Pocknall and Mildenhall 1984). ...
At least seven foliar taxa of Proteaceae occur in Oligo-Miocene lignite from the Newvale site. These taxa include two new species of the fossil genus Euproteaciphyllum, and previously described species of tribe Persoonieae and Banksia. Other specimens from Newvale are not assigned to new species, but some conform to leaves of the New Caledonian genus Beauprea, which is also represented in the lignite by common pollen. Two other Euproteaciphyllum species are described from the early Miocene Foulden Maar diatomite site. One of these species may belong to Alloxylon (tribe Embothrieae) and the other to tribe Macadamieae, subtribe Gevuininae. Ecologically, the species from Newvale represented important components of wet, oligotrophic, open vegetation containing scleromorphic angiosperms and very diverse conifers. In contrast, Proteaceae were large-leaved and rare in Lauraceae-dominated rainforest at the volcanic Foulden Maar site. Overall, the Oligo-Miocene fossils confirm that Proteaceae was formerly much more diverse and dominant in the New Zealand vegetation, and provide fossil evidence for biome conservatism in both leaf traits and lineage representation.
... Knowledge is fragmentary at best, due to the absence of a complete spatial and temporal record. Furthermore, conclusions have been based primarily on Quaternary studies (Churchill, 1956;1961;Newsome and Pickett, 1993;Pickett, 1997;Pickett and Newsome, 1997;Dodson and Lu, 2000), with more recent Pliocene insights (Bint, 1981;Dodson and Ramrath, 2001) and several Eocene taxonomic palynological studies (Cookson, 1954;Balme and Churchill, 1959;Hos, 1975;Bint, 1981;Milne, 1981;Stover and Partridge, 1982;Milne, 1988;Milne and Martin, 1998), and some macrofossil studies (for example Hill and Merrifield, 1994;Carpenter and Pole, 1995). ...
South-western Australia is a globally significant hotspot of Proteaceae diversity. This review reports on changes in the abundance and diversity of Proteaceae in south-western Australia. Using palynology, the data were obtained from three sediment sequences from the Eocene, Pliocene and Holocene, as well as a modern pollen rain study, in the context of a vegetation history framework. The total percentages of Proteaceae pollen in pollen counts indicate that the number of Proteaceae in the vegetation are highest at present, slightly lower, yet still high in the Eocene, reduced by the Pliocene and lowest in the Holocene. It was found that Proteaceous genera can contribute up to 50% of the total modern pollen rain. Sediment from Lake Lefroy showed Nothofagus-dominated rainforest occurred in the Middle to Late Eocene. Proteaceae species were at least as diverse as today, contributing up to a maximum of 42% of the total pollen rain, and varying across small lateral distances. A laminated Pliocene age sequence from Yallalie confirmed other studies that south-western Australia was covered by a rich vegetation mosaic consisting of heath and wet rainforest elements. Proteaceae species were a consistent component of the counts, although diversity and abundance (maximum 5%) were low. A Holocene record from Two Mile Lake, near the Stirling Range, recorded little environmental change. Proteaceae species were noted in low abundance, at a maximum of 3.5% of the total pollen count. It is likely that both changing pollination mechanisms and changes in associated vegetation are important in determining the dispersal of Proteaceous pollen.
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... The remaining three specimens have different sculpture and more pronounced apertural nexine thickening, and are referred to Proteacidites marginatus Milne,. The study of extant Conospermeae pollen, in particular those of 40 Petrophile species (Milne 1997;Milne and Martin 1998), showed that sculptural detail is relatively consistent within a species, and although aperture type is also species-indicative, its form is dependent on grain and/or aperture maturation. Differing aperture maturation is illustrated by single grains of P. carobelindiae that possess more than one aperture form (e.g. ...
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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.
The centres of diversification of the iconic family Proteaceae are in South Africa and southern Australia. Since the ancestors of the family can be traced to NW Africa our task was to explain how all subfamilies (Proteoideae, Grevilleoideae, Persoonioideae) managed to reach Australia and we propose the pathway: (Africa(N South America(S South America(Antarctica (Australia))))). Our dated molecular phylogeny showed that the family arose 132 million years ago (Ma), and by 125 Ma had separated into the three subfamilies that remain dominant today.
The age and location of records for 420 fossil pollen with Proteaceae affinities were collated per continent and submitted to curve-fitting analysis. This showed spread of early Proteaceae into N South America from ~121 Ma that was able to continue for another 20–25 My. These three subfamilies (plus Carnarvonia) travelled south through South America and Antarctica, crossing the Weddellian Isthmus from ~110 Ma, to reach southern Australia by ~104 Ma. The history of Proteaceae in South America mimics that of Africa, where Grevilleoideae diversified instead of Proteoideae that died out. Entry to Australia via Antarctica was possible until ~70 Ma at its SW corner and 45 Ma at its SE (Tasmanian) corner enabling the three subfamilies (and Carnarvonia) restricted entry into Australia over 35–60 My.
The SW Australian sclerophyll flora became the centre of diversification and emigration at the species level of all but the rainforest (malacophyll) Grevilleoid/Proteoid clades within Australia. Close genetic links between clades in South Africa (the centre of diversification of the sclerophyll flora in Africa) and SW Australia are the product of disparate migratory histories from their common ancestor in NW Africa, differential survival among subfamilies and parallel evolution in matched environments. E Australia became the centre of diversification at the subtribe level. Close genetic links between clades in South America and E Australia are the product of long-distance dispersal from their common ancestor in N South America, genetic stability in matched environments and eventual vicariance.
In this paper, the fourth in a series documenting palynological characters across angiosperms using a contemporary phylogenetic framework, we deal with the basal eudicots, a group which includes Buxales, Proteales, Ranunculales, Sabiaceae, and Trochodendrales. Using available molecular sequences of matK and rbcL from previous studies, we reconstructed a maximum likelihood tree for a total of 196 genera (including nine outgroups), representing 13 families and all four orders of basal eudicots. Across the 196 genera, 20 pollen characters were documented from prior publications and new observations. These were coded using two strategies and optimized onto the reconstructed phylogenetic tree using Fitch parsimony, maximum likelihood, and hierarchical Bayesian inference to infer ancestral states. Pollen samples of 24 species from 24 genera in eight families were imaged under LM and SEM to illustrate the diversity of basal eudicot pollen. In addition, we tested for correlated evolution between plant growth form and pollen shape class, and between anemophily and pollen aperture number, using maximum likelihood and Markov chain Monte Carlo analyses. Basal eudicot pollen showed high morphological diversity, especially in characters including tectum sculpture, aperture number, and ectoaperture shape. Depending upon the method of reconstruction, 14 to 18 plesiomorphic palynological states were unequivocally inferred, and a total number of 357 character state transitions were found at or above tribal level. These provide palynological support for at least 58 of the clades discovered by molecular phylogenetic estimation. For example, using hierarchical Bayesian inference with comprehensive data coding, 222 state changes were inferred. Pollen size, tectum sculpture, and pollen shape class changed the most frequently among the 20 studied characters. The most concentrated character state changes in basal eudicot pollen are estimated to have occurred around the Barremian to Albian stages of the Early Cretaceous. Tests of correlated evolution suggest that the herbaceous growth form is significantly associated with spheroidal pollen shape and the arborescent growth form with oblate pollen shape. However, no significant correlations were found between anemophily and aperture number. Patterns of evolutionary change in pollen size and tectum sculpture, and their adaptive functions, are discussed. Based on previous evidence and our data, pollination syndrome is the most likely factor associated with the high frequency of state changes in these two characters.
The spatial and temporal vegetation and environmental dynamics of an Eocene sequence from south-western Australia, based on pollen and geochemical analyses, is presented here. The vegetation was dominated by Nothofagus species with other gymnosperms such as Araucaria and Podocarpus intermixed with Myrtaceae, Proteaceae and Casuarinaceae. Pollen of Proteaceae were an important and consistent component of the vegetation; as much, or more so than at present. Results from this study show that the Proteaceous component is up to 42% of the total pollen counts. Removing data for the dominant Nothofagus taxon did not alter the apparent dominance of Proteaceae species, though the abundance and types of species changed. The abundance and diversity of the flora here supports the view that there are differences between the flora in eastern and western parts of Australia at this time. In addition, a main finding of this research is that there can be considerable spatial and temporal variability in the abundance and diversity of taxa, and specifically Proteaceous taxa, in landscapes in the Eocene.
Proteoideae (27 genera, 655 species) are one of the largest clades in the early-diverging eudicot family Proteaceae and are distributed in Australia, New Caledonia, and Africa. New palynological observations using scanning and transmission electron microscopy are reported for 15 genera and 49 species, which complement previous work on the subfamily. These are integrated with an extensive review of all literature data available to provide a summary of pollen morphology and variation in each genus of Proteoideae, using a new rigorous method of character scoring. The results are discussed in the context of recent phylogenetic analyses of Proteaceae. The monophyletic Leucadendreae, comprising two Australian genera and a large clade of 10 southern African genera, appear to be relatively homogenous in pollen morphology, especially in ultrastructure of the apertural region. In addition, two other African genera, Faurea and Protea, share very similar pollen characters, some of which appear to be apomorphic, consistent with strong phylogenetic evidence for their sister group relationship. Beauprea, Eidothea, Faurea, Protea, and Stirlingia share a distinct pattern of foot layer disintegration at the apertural region and complete lack of endexine. The occurrence of the same apertural type in the early-diverging Persoonioideae suggests that it is plesiomorphic in Proteoideae and Proteaceae as a whole. This study highlights the phylogenetic potential of ultrastructural characters in Proteaceae and high levels of homoplasy and polymorphism in other characters including pollen shape and tectum sculptural patterns.
