Cycadopsida - Cycadales - Nilssoniaceae
Parent taxon: Cycadales according to W. B. K. Holmes 1982
See also Peppe et al. 2007
Sister taxa: Amuriella, Anthrophyopsis, Apoldia, Archaeocycas, Aricycas, Beaniaceae, Behuninia, Bucklandia, Bureja, Cavamonocolpites, Crossozamiaceae, Ctenozamites, Cycadaceae, Cycadenia, Cycadinorachis, Dirhopalostachyaceae, Eucommiidites, Fascisvarioxylon, Gymnovulites, Haitingeria, Heilungia, Mesosingeria, Michelilloa, Nikania, Nilsonia, Palaeozamia, Paracycas, Phasmatocycas, Pleiotrichium, Sarmatiella, Stangerites, Sueria, Taeniopteris, Zamiaceae
Subtaxa: Nilssoniocladus Pseudoctenis
Distribution:
• Cretaceous of Antarctica (1 collection), Canada (8: British Columbia), Greenland (2), India (4), the Russian Federation (1), South Africa (4), United States (7: North Dakota, Wyoming)
• Jurassic to Cretaceous of Canada (1: British Columbia)
• Jurassic of Antarctica (2), Argentina (1), China (4), France (2), Georgia (6), Greenland (2), India (1), Iran (2), Japan (7), Kazakhstan (3), Mexico (4), Norway (1), Romania (6), the Russian Federation (10), Tajikistan (1), Ukraine (1), the United Kingdom (31), Uzbekistan (1)
• Triassic to Jurassic of Sweden (1)
• Triassic of Argentina (4), Australia (3), Chile (2), China (3), Germany (1), Greenland (8), Mongolia (1), the Russian Federation (3), South Africa (21), Sweden (1), Tajikistan (3), United States (4: New Mexico, North Carolina)
• Permian to Triassic of India (1)
• Permian of Australia (4), India (9), the United Kingdom (1)
Total: 183 collections including 224 occurrences