''Pachypteris'' ( Brongn.) T.M.Harris. is a

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...

pteridosperm The term Pteridospermatophyta (or "seed ferns" or "Pteridospermatopsida") is a polyphyletic group of extinct seed-bearing plants (spermatophytes). The earliest fossil evidence for plants of this type is the genus ''Elkinsia'' of the late Devonian ...

leaf fossil probably belonging to the

seed fern A seed is an Plant embryogenesis, embryonic plant enclosed in a testa (botany), protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, includ ...

Order

Peltaspermales The Peltaspermales are an extinct order of plants belonging to Pteridospermatophyta, or seed ferns. It is unclear whether they form a natural group of organisms as they are poorly known. They span from the Late Carboniferous to the Early Jurassi ...

Description

''Pachypteris'' is represented by hypostomatic, bipinnate or unipinnate leaves, with alethopteridian venation (midvein and secondary veins divided once or twice before reaching the pinnule margin), pinnules with entire margins and rounded apices. The stomata are haplocheilic, monocyclic or dicyclic, usually depressed, with the guard cells occurring in the lowermost part of the stoma.

Taxonomy

The affinities of ''Pachypteris'' lay with '' Cycadopteris'', '' Komlopteris'', ''

Dicroidium ''Dicroidium'' is an extinct genus of fork-leaved seed ferns that were widely distributed over Gondwana during the Triassic (). Their fossils are known from South Africa, the Arabian Peninsula, Australia, New Zealand, South America, Madagascar ...

'' (a typical Corystospermalean foliage) and '' Ptilozamites''. It includes the former denomination ''Thinnfeldia'' Ettingshausen 1852, a junior synonym of ''Pachypteris'', as Doludenko (1971) showed. The genus was detailed by Harris (1964), Doludenko (1974), Schweitzer and Kirchner (1998), Popa (2000), and Gordenko (2007). The genus ''Komlopteris'', a segregate from ''Pachypteris'', was defined by Barbacka (1994).Barbacka, M., 1994. ''Komlopteris'' Barbacka, gen. nov., a segregate from ''Pachypteris'' Brongniart. Review of Palaeobotany and Palynology(83): 339-349. ''Pachypteris'' includes about 20 species ranging from late

Triassic The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...

to Lower

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

, such as ''P. speciosa'', ''P. rhomboidalis'', ''P. gradinarui'', etc. This genus is mainly a boreal taxon, being extensively reported in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...

, China and North America, but it has been cited from Gondwanic occurrences as well, such as

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

and Australia.

Distribution

Fossils of ''Pachypteris'' have been registered in:''Pachypteris''
at Fossilworks.org ;Triassic Brazil, China, Germany, Japan, and the Russian Federation ;Jurassic 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. ;Cretaceous Argentina

References

{{Taxonbar, from=Q7122207 Pteridospermatophyta Early Triassic genus first appearances Olenekian genera Anisian genera Ladinian genera Carnian genera Norian genera Rhaetian genera Hettangian genera Sinemurian genera Pliensbachian genera Toarcian genera Aalenian genera Bajocian genera Bathonian genera Callovian genera Oxfordian genera Kimmeridgian genera Tithonian genera Berriasian genera Valanginian genera Hauterivian genera Barremian genera Aptian genera Albian genera Cenomanian genera Triassic plants Jurassic plants Early Cretaceous plants Late Cretaceous plants Late Cretaceous genus extinctions Mesozoic Antarctica Mesozoic life of Asia Mesozoic life of Europe Mesozoic life of South America Prehistoric plants of South America Triassic Brazil Fossils of Brazil Jurassic Argentina Cretaceous Argentina Fossils of Argentina Jurassic Colombia Fossils of Colombia Fossil taxa described in 1828 Fossils of Serbia