Pteruchus africanus

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Pteruchus africanus
Temporal range: Triassic
Pteruchus africanus.jpg
Pteruchus africanus fossil pollen organ, Late Triassic, Molteno Formation, Umkomaas, South Africa.
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Order: Peltaspermales
Family: Corystospermaceae
Genus: Pteruchus
Species:
P. africanus
Binomial name
Pteruchus africanus
Thomas [1]

Pteruchus africanus is a pollen organ of a seed fern (Pteridospermatophyta). It was first described by Hamshaw Thomas [1] from the Umkomaas locality of South Africa.

Contents

Umkomasia macleani reconstruction of whole plant including leaves (Dicroidium odontopteroides, pollen organs (Pteruchus africanus based largely on material from the Umkomaas locality of South Africa Umkomasia macleani reconstruction.jpg
Umkomasia macleani reconstruction of whole plant including leaves ( Dicroidium odontopteroides , pollen organs (Pteruchus africanus based largely on material from the Umkomaas locality of South Africa

Description

The pollen organs Pteruchus africanus differ from other species of Pteruchus in small size, and equant blade supporting the pollen sacs.

Whole plant reconstructions

Pteruchus africanus may have been produced by the same plant as Umkomasia macleanii (ovulate organs) and Dicroidium odontopteroides (leaves), based on cuticular similarities between these leaves and reproductive structures at the Umkomaas locality of South Africa. [1]

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<i>Dicroidium</i> Extinct genus of seed ferns

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<i>Umkomasia</i> Extinct genus of seed ferns

Umkomasia is a genus of seed bearing organs produced by corystosperm seed ferns, first based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. He recognized on the basis of cuticular similarities that the same plant produced pollen organs Pteruchus and the leaves Dicroidium. Various other corystosperm seed bearing organs from the Jurassic and Cretaceous have been assigned to this genus, but recently have been given distinct genera, with Umkomasia being restricted to the Triassic.

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Dictyopteridium is an extinct genus of plants belonging to Glossopteridaceae, but the name is used only for compression fossils of elongate multiovulate reproductive structures adnate to Glossopteris leaves. Permineralized remains identical to Dictyopteridium have been referred to the organ genus Homevaleia

<i>Lagenostoma</i> Extinct genus of seed ferns

Lagenostoma is a genus of seed ferns (Pteridospermatophyta), based on ovules preserved in coal balls from the Six Inch Coal of the Hough Hill Colliery near Stalybridge, England. Distinctive stalked glands enabled Oliver and Scott to attribute these seeds to fernlike foliage of Sphenopteris hoeningshauseni in the same coal balls. This was the first recognition that some Carboniferous fernlike leaves had seeds, and so were not pteridophytes, but rather Pteridospermatophyta, or seed ferns. The realization that seed plants as well as spore plants had fernlike leaves was a major contribution to the evolutionary history of plants.

References

  1. 1 2 3 Thomas, .H. (1933). "On some pteridospermous plants from the Mesozoic rocks of South Africa". Philosophical Transactions of the Royal Society B. 222 (483–493): 193–265. doi: 10.1098/rstb.1932.0016 .
  2. Retallack, G.J. & Dilcher, D.L (1988). "Reconstructions of selected seed ferns". Annals of the Missouri Botanical Garden. 75 (3): 1010–1057. doi:10.2307/2399379. JSTOR   2399379.