Corystospermaceae

Corystosperms are a group of extinct seed plants belonging to the family Corystospermaceae assigned to the order Corystospermales[2] or Umkomasiales.[3] They were first described based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa.[4] Corystosperms are typified by a group of plants that bore forked Dicroidium leaves, Umkomasia cupulate ovulate structures and Pteruchus pollen organs, that were widespread over Gondwana during the Middle and Late Triassic. Other fossil Mesozoic seed plants with similar reproductive structures have also sometimes been included within the "corystosperm" concept sensu lato, such as the "doyleoids" from the Early Cretaceous of North America and Asia.[3] Their oldest records date to the Late Permian from the Umm Irna Formation of Jordan, as well as Pakistan.[5][6] Late surviving Dicroidium-bearing corystosperms are known from the Early Jurassic (Sinemurian) of East Antarctica.[7] A potential corystosperm sensu lato, the leaf fossil Komlopteris cenozoicus, is known from the Eocene of Tasmania, at least 13 million years after the Cretaceous–Paleogene extinction event.[8]

Umkomasia macleanii ovulate structure from the Late Triassic, Molteno Formation of Umkomaas, South Africa

Corystospermaceae Temporal range:
Umkomasia macleanii reconstructed plant, Late Triassic, Molteno Formation, Umkomaas, South Africa. Including Dicroidium leaves (D), Umkomasia ovulate organ (L-P), and Pteruchus pollen organ (H-K)[1]
Scientific classification
Kingdom:	Plantae
Order:	†Corystospermales
Family:	†Corystospermaceae Thomas 1933
Genera
Umkomasia ovulate structures Pteruchus pollen organs Dicroidium leaves Johnstonia leaves Xylopteris leaves Kyklyxylon wood Antarcticoxylon wood Rhexoxylon wood "Doyleoids" (sometimes included) Doylea ovulate structures Jarudia ovulate structures Tevshiingovia ovulate structures
Synonyms
Umkomasiaceae Petriella, 1981