List of extinct cycad genera

Numerous genera of extinct cycads are known, dating variously to geological periods from the Permian to the Cretaceous.^[1]

Alphabetical list

• Amuriella Late Jurassic, Russian Far East (leaf fragments)
• Androstrobus Triassic to Cretaceous, worldwide (leaf form genus)
• Antarcticycas Middle Triassic, Antarctica (known from the whole plant)^[2]
• ?Anthrophyopsis Late Triassic, worldwide (leaf form genus, possibly a pteridospermatophyte)^[3]
• Apoldia Triassic-Jurassic, Europe
• Archaeocycas Early Permian, Texas (leaf with sporophylls)
• Aricycas Late Triassic, Arizona (leaf form genus)
• Beania (=Sphaereda), Triassic to Jurassic, Europe & Central Asia (leaf form genus)
• Behuninia Late Jurassic, Colorado & Utah (fruiting structures)
• Bucklandia Middle Jurassic to Early Cretaceous, Europe and India (leaf form genus)
• Bureja Late Jurassic, Russia
• Bjuvia Late Permian to Jurassic, Europe & North America^[4]
• Cavamonocolpites Early Cretaceous, Brazil (pollen)
• Crossozamia Early to Late Permian, China (leaf form genus)
• Ctenis Mesozoic-Paleogene, Worldwide (leaf form genus)
• Ctenozamites Triassic-Cretaceous, worldwide (leaf form genus)
• Cycadenia Triassic, Pennsylvania (trunks)
• Cycadinorachis Late Jurassic, India (rachis)
• Fascisvarioxylon Late Jurassic, India (petrified wood)
• Gymnovulites, Latest Cretaceous/earliest Paleocene, India (seed)
• Heilungia, Late Jurassic to early Cretaceous, Russia & Alaska (leaf form genus)
• Leptocycas Late Triassic, North Carolina & China (known from the whole plant)^[5]
• Mesosingeria, Jurassic to Early Cretaceous, Antarctica & Argentina (leaf form genus)
• Michelilloa, Late Triassic, Argentina (stem)
• ?Nikania, Early Cretaceous, Russia (leaf fragments)
• ?Nilssonia, Middle Permian to Late Cretaceous, worldwide (leaf form genus) (possibly not a cycad)^[6]
• ?Nilssoniocladus, Early to Late Cretaceous, United States & Russia (stems, likely associated with Nilssonia, possibly deciduous)^[7]
• Palaeozamia, Middle Jurassic, England
• Paracycas, Middle Jurassic to Late Jurassic, Europe and Central Asia
• ?Phasmatocycas, Late Carboniferous to Early Permian, Kansas, Texas & New Mexico (leaf with sporophylls)^[8]
• Pleiotrichium, Late Cretaceous, Germany (leaf)
• Pseudoctenis, Late Permian to Late Cretaceous, worldwide (leaf form genus)
• Sarmatiella, Late Triassic, Ukraine
• Stangerites, Late Triassic to Early Jurassic, Virginia and Mexico (leaf form genus)
• Sueria, Early Cretaceous, Argentina (leaf)
• Taeniopteris, Carboniferous to Cretaceous, worldwide (polyphyletic leaf form genus, also includes bennettitales and marattialean ferns)