Pachypteris

The stomata are haplocheilic, monocyclic or dicyclic, usually depressed, with the guard cells occurring in the lowermost part of the stoma.

The affinities of Pachypteris lay with Cycadopteris, Komlopteris, Dicroidium (a typical Corystospermalean foliage) and Ptilozamites.

[9] Pachypteris includes about 20 species ranging from late Triassic to Lower Cretaceous, such as P. speciosa, P. rhomboidalis, P. gradinarui, etc.

This genus is mainly a boreal taxon, being extensively reported in Europe, Iran, Afghanistan, China and North America, but it has been cited from Gondwanic occurrences as well, such as India, Argentina and Australia.

Fossils of Pachypteris have been registered in:[10] Brazil, China, Germany, Japan, and the Russian Federation Antarctica, Argentina, Australia, Colombia (Valle Alto Formation, Caldas), France, Georgia, India, Iran, Italy, Japan, Lithuania, Norway, Poland, Romania, the Russian Federation, Serbia and Montenegro, Tajikistan, the United Kingdom, and Uzbekistan.