Parent taxon: Voltziopsida according to A. B. Doweld 2001
See also Taylor et al. 2008
Sister taxa: Ferugliocladales, Palissyales, Ullmanniales
Subtaxa: Bartheliaceae Emporiaceae Moyliostrobus Pseudovoltzia Rotundolepis Thucydiaceae Ullmanniaceae Utrechtiaceae Voltziaceae
Distribution:
• Triassic of Argentina (1 collection), Austria (1), Chile (1), China (3), France (3), Germany (17), Hungary (1), Iran (1), Italy (18), Kyrgyzstan (1), New Zealand (1), the Russian Federation (1), Serbia and Montenegro (1), South Africa (18), Spain (1), Switzerland (2), Ukraine (1), the United Kingdom (2), United States (2: North Carolina)
• Permian of Brazil (3), China (2), Germany (10), Hungary (1), India (2), Italy (1), Kenya (1), Madagascar (4), Peru (1), the Russian Federation (6), Saudi Arabia (2), the United Kingdom (5), United States (4: Arizona, Colorado, Kansas, Texas)
• Carboniferous of United States (1: Arizona)
Total: 119 collections including 142 occurrences