Dicroidium

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Dicroidium
Temporal range:
Late Permian–Sinemurian
Dicroidium odontopteroides fossil leaf, Late Triassic Molteno Formation near Birds River South Africa.
Scientific classification Edit this classification
Kingdom: Plantae
Order: Corystospermales
Family: Corystospermaceae
Genus: Dicroidium
Gothan (1912)
Species
  • Dicroidium crassinervis Australia, Antarctica, South Africa
  • Dicroidium coriaceum, Australia, Antarctica, South Africa
  • Dicroidium dubium Australia, Antarctica, South Africa
  • Dicroidium odontopteroides, Australia, New Zealand, Antarctica, India, South Africa, Argentina, Brazil[1]
  • Dicroidium stelznerianum, Australia, New Zealand, Antarctica, South Africa, Argentina[2]
Synonyms
  • Johnstonia Walkom
  • Harringtonia Frenguelli
  • Dicroidiopsis Frenguelli
  • Diplasiophyllum Frenguelli
  • Zuberia Frenguelli
  • Xylopteris Frenguelli
  • Tetraptilon Frenguelli
  • Hoegia Townrow
  • Jordaniopteris Anderson

Dicroidium is an extinct genus of fork-leaved

seed ferns", assigned to the order Corystospermales or Umkomasiales. Species of Dicroidium were widely distributed and dominant over Gondwana during the Triassic (252 to 201 million years ago). Their fossils are known from South Africa, the Arabian Peninsula, Australia, New Zealand, South America, Madagascar, the Indian subcontinent and Antarctica
.

Description

venation of the leaves is also highly variable, encompassing taeniopteroid, odontopteroid, alethopteroid and simple morphologies.[5]

Whole plant

Reconstruction of the whole plant of Dicroidium odontopteroides , including Umkomasia macleanii (L-P) and Pteruchus africanus (H-K)

Dicroidium plants grew as medium-large sized trees,

wind dispersed.[4]

Possible whole plant associations include:

Evolution

The earliest Dicroidium species are known from the

end-Triassic mass extinction, with Dicroidium surviving in parts of East Antarctica into the Early Jurassic (Sinemurian).[5]

References

  • Bomfleur, B. and Kerp, H. (2010). Dicroidium diversity in the Upper Triassic of north Victoria Land, East Antarctica.