''Sagenopteris'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of extinct seed ferns from the

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

to late

Early Cretaceous The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pr ...

.''Sagenopteris''
at

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.org

Description

''Sagenopteris'' has palmately arranged leaves with anastomosing venation. Different organs attributed to the same original plant can be reconstructed from co-occurrence at the same locality and from similarities in the stomatal apparatus and other anatomical peculiarities of fossilized cuticles. * '' Sagenopteris phillipsii'' may have been produced by the same plant as '' Caytonia nathorstii'' (ovulate organs) and '' Caytonanthus arberi'' (pollen organs).

Species

The following species have been described: * ''Sagenopteris colpodes'' * ''Sagenopteris elliptica'' * ''Sagenopteris mclearni'' * ''Sagenopteris nilssoniana'' * ''Sagenopteris oregonensis'' * '' Sagenopteris phillipsii'' * ''

Sagenopteris trapialensis ''Sagenopteris trapialensis'' are leaves of extinct species of seed fern from Chubut, Patagonia Argentina. At the moment, ''S. trapialensis'' is based on impression fossils found in the Early Jurassic Lonco Trapial Formation A lonko or lonco ...

'' * ''Sagenopteris variabilis'' * ''

Sagenopteris williamsii ''Sagenopteris williamsii'' is an extinct pteridosperm (seed fern) that is known from the late Jurassic and Early Cretaceous strata of the western interior of North America. It was first described as ''Chiropteris williamsii'' by J.S. Newber ...

''Bell, W.A. 1956. Lower Cretaceous floras of western Canada;

Geological Survey of Canada The Geological Survey of Canada (GSC; french: Commission géologique du Canada (CGC)) is a Canadian federal government agency responsible for performing geological surveys of the country, developing Canada's natural resources and protecting the e ...

, Memoir 285, p. 80-81 and plates 31, 33, 34, and 36.

Distribution

Fossils of ''Sagenopteris'' have been registered in: ;Triassic Argentina, China, Germany, Greenland, Italy, Japan, Kyrgyzstan, the Russian Federation, Sweden, Tajikistan, Ukraine, United States (Virginia, Virginia/North Carolina). ;Jurassic (to Cretaceous) Afghanistan, Antarctica, Argentina, Azerbaijan, Belarus, Canada (British Columbia, Yukon), China, Colombia (

Valle Alto Formation The Valle Alto Formation ( es, Formación Valle Alto, Jva) is a geological formation of the Central Ranges of the Colombian Andes. The formation is composed of shales, sandstones and conglomerates and dates to the Late Jurassic period. Ammoni ...

, Caldas), Georgia, Germany, Greenland, India, Iran, Italy, Japan, Kazakhstan, Kyrgyzstan, Mexico, Peru, Poland, Romania, the Russian Federation, Tajikistan, Turkmenistan, Ukraine, the United Kingdom, United States (Alaska, Montana, Oregon/Idaho), and Uzbekistan. ;Cretaceous Belgium, Canada (British Columbia and Alberta), Greenland, the Russian Federation, and the United States (Montana).

References

Pteridospermatophyta Triassic first appearances Triassic plants Jurassic plants Early Cretaceous plants Early Cretaceous genus extinctions Prehistoric plant genera Fossil record of plants Mesozoic Antarctica Mesozoic life of Asia Mesozoic life of Europe Mesozoic life of North America Prehistoric plants of North America Jurassic Canada Jurassic Mexico Jurassic United States Prehistoric plants of South America Mesozoic life of South America Triassic Argentina Jurassic Argentina Fossils of Argentina Jurassic Colombia Fossils of Colombia Jurassic Peru Fossils of Peru Fossil taxa described in 1838 {{cretaceous-plant-stub