Is the anthophyte hypothesis alive and well? New evidence from the reproductive structures of Bennettitales.

@article{Rothwell2009IsTA,
  title={Is the anthophyte hypothesis alive and well? New evidence from the reproductive structures of Bennettitales.},
  author={Gar W Rothwell and W. Crepet and Ruth A. Stockey},
  journal={American journal of botany},
  year={2009},
  volume={96 1},
  pages={
          296-322
        }
}
Bennettitales is an extinct group of seed plants with reproductive structures that are similar in some respects to both Gnetales and angiosperms, but systematic relationships among the three clades remain controversial. This study summarizes characters of bennettitalean plants and presents new evidence for the structure of cones and seeds that help clarify relationships of Bennettitales to flowering plants, Gnetales, and other potential angiosperm sister groups. Bennettitales have simple mono… 

Molecular and Fossil Evidence on the Origin of Angiosperms

Molecular data on relationships within angiosperms confirm the view that their increasing morphological diversity through the Cretaceous reflected their evolutionary radiation. Despite the early

Evolution and Phylogeny of Gnetophytes: Evidence from the Anatomically Preserved Seed Cone Protoephedrites eamesii gen. et sp. nov. and the Seeds of Several Bennettitalean Species

Comparisons to several species of Bennettitales confirm that there are fundamental structural differences separating the seeds of Gnetales from those of BennettITALes, support the hypothesis that the outer seed envelope evolved within the gnetophyte clade, and suggest thatennettitales are not as closely related to G netales as hypothesized by some authors.

Distinguishing angiophytes from the earliest angiosperms: A Lower Cretaceous (Valanginian-Hauterivian) fruit-like reproductive structure.

They show that nearly total ovule enclosure, a level of organization approaching angiospermy, was achieved by advanced seed ferns during the Mesozoic, and include tetrahedral seeds within cupule- or carpel-like structures.

The First Organismal Concept for an Extinct Species of Pinaceae: Pinus arnoldii Miller

The Eocene Princeton Chert locality of southern British Columbia, Canada, provides data to develop organismal concepts for several species of fossil plants, including the first extinct species of

Ancestral traits and specializations in the flowers of the basal grade of living angiosperms

An updated review of floral morphology and its evolution in the basal ANITA grade of living angiosperms, Chloranthaceae, and Ceratophyllum, which concludes that phyllotaxis is complex whorled in Nymphaeales and spiral in Amborella and Austrobaileyales.

Chlamydospermous Seeds Document the Diversity and Abundance of Extinct Gnetalean Relatives in Early Cretaceous Vegetation

Most of the fossils exhibit combinations of features that are unknown among extant species of Gnetales and clearly represent an extinct complex of plants that were important in Early Cretaceous vegetation, along with other extinct plant groups, including Bennettitales and Erdtmanithecales.

Gnetum and Nymphaeaceans as Models for a Scenario of the Origin of Morphotype of Flowering Plants

A morphological analysis of the available data shows that the true angiosperm ancestor must have differed from Gnetum in some important respects, e.g., it must have had a more primitive xylem and bisexual fructifications.

Molecular and Fossil Evidence on the Origin of Angiosperms

  • J. Doyle
  • Environmental Science, Geography
  • 2012
Molecular data on relationships within angiosperms confirm the view that their increasing morphological diversity through the Cretaceous reflected their evolutionary radiation and appear to refute the hypothesis based on morphology that angiosPerms and Gnetales are closest living relatives.

New Diversity among Chlamydospermous Seeds from the Early Cretaceous of Portugal and North America

The distinctive organization of the seeds seen in Tomcatia, Cattomia, Acanthocatia, and Quadrispermum links them to previously described seeds of Erdtmanithecales and Gnetales, and provides further evidence of a close relationship of some of the dispersed seeds to Bennettitales.
...

References

SHOWING 1-10 OF 82 REFERENCES

Seed ferns and the origin of angiosperms

Analysis of a critically revised morphological data set for seed plants indicates that trees in which Gnetales are nested in conifers, as in molecular analyses, are almost as parsimonious as those inWhich G netales are linked with angiosperms, suggesting that the molecular arrangement should be accepted.

Seed plant phylogeny and the origin of angiosperms: An experimental cladistic approach

The results raise the possibility that many features considered key adaptations in the origin and rise of angiosperms were actually inherited from their gymnospermous precursors, and the morphological diversity of Mesozoic anthophytes could provide critical tests of relationships.

Distinguishing angiophytes from the earliest angiosperms: A Lower Cretaceous (Valanginian-Hauterivian) fruit-like reproductive structure.

They show that nearly total ovule enclosure, a level of organization approaching angiospermy, was achieved by advanced seed ferns during the Mesozoic, and include tetrahedral seeds within cupule- or carpel-like structures.

The Mostly Male Theory of Flower Evolutionary Origins: from Genes to Fossils

The authors' data from the homeotic gene Floricaula/LEAFY imply that the lineage leading to flowering plants originally had two copies of this gene, but that one copy was lost in flowering plants, which suggests a new theory: that developmental control of flower organization derives more from systems active in the male reproductive structures of the gymnosperm ancestor, rather than from the female, with ovules being ectopic in the original flower.

Seed plant phylogeny inferred from all three plant genomes: monophyly of extant gymnosperms and origin of Gnetales from conifers.

The Gnetales may be viewed as extremely divergent conifers, and the many morphological similarities between angiosperms and G netales arose independently.

Molecules, morphology, fossils, and the relationship of angiosperms and Gnetales.

  • J. Doyle
  • Biology
    Molecular phylogenetics and evolution
  • 1998
Even if molecular data resolve the relationships among living seed plant groups, understanding of the origin of angiosperm organs will require integration of fossil taxa, necessarily using morphology.

Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants

It is shown that there are three monophyletic groups of extant vascular plants: (1) lycophytes, (2) seed plants and (3) a clade including equisetophytes (horsetails, psilotophytes) and all eusporangiate and leptosporangiates ferns.

[Morphological and molecular data on the origin of angiosperms: on a way to a synthesis].

Traditional botanical and paleobotanical data should not be rejected and Meyen's idea angiosperms origin from Bennettitales is worth being retained as a hypothesis to be tested with new results of both Paleobotany and molecular biology.

Anatomically preserved Cycadeoidea (Cycadeoidaceae), with a reevaluation of systematic characters for the seed cones of Bennettitales.

Four anatomically preserved ovulate cycadeoid cones have been recovered from three localities in Upper Cretaceous sediments of Vancouver and Hornby Islands, British Columbia, Canada, revealing details of the reproductive biology shortly before extinction of the clade.
...