Dicroidium

Dicroidium Temporal range: Late Permian–Sinemurian PreꞒ Ꞓ O S D C P T J K Pg N
Leaf impression of Dicroidium zuberi
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
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] Dicroidium zuberi, Antarctica, Australia, South Africa, Brazil[3]
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 plants. It is the archetypal genus of the corystosperms, an extinct group of seed plants, often called "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.