Sagenopteris

Sagenopteris Temporal range: Triassic-Early Cretaceous ~242–105 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Sagenopteris phillipsii leaves, Middle Jurassic, Gristhorpe Bed, Cloughton Formation, Cayton Bay, Yorkshire.
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	†Pteridospermatophyta
Order:	†Caytoniales
Family:	†Caytoniaceae
Genus:	†Sagenopteris Presl 1838
Species
See text

Sagenopteris is a genus of extinct seed ferns from the Triassic to late Early Cretaceous.[1][2]

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).[3]

Species

The following species have been described:[1]

• Sagenopteris colpodes
• Sagenopteris elliptica
• Sagenopteris mclearni
• Sagenopteris nilssoniana
• Sagenopteris oregonensis
• Sagenopteris phillipsii
• Sagenopteris trapialensis[2]
• Sagenopteris variabilis
• Sagenopteris williamsii[4]

Distribution

Fossils of Sagenopteris have been registered in:[1]

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, 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

Spain, Belgium, Canada (British Columbia and Alberta),[4] Greenland, the Russian Federation, and the United States (Montana).

References

1. Sagenopteris at Fossilworks.org
2. Elgorriaga, A.; Escapa, I. H.; Cúneo, R. (2019). "Southern Hemisphere Caytoniales: vegetative and reproductive remains from the Lonco Trapial Formation (Lower Jurassic), Patagonia". Journal of Systematic Palaeontology. 17 (17): 1477–1495. Bibcode:2019JSPal..17.1477E. doi:10.1080/14772019.2018.1535456. S2CID 92287804.
3. Retallack, G.J. & Dilcher, D.L. (1988). "Reconstructions of selected seed ferns". Missouri Botanical Garden Annals. 75 (3): 1010–1057. doi:10.2307/2399379. JSTOR 2399379.
4. Bell, W.A. 1956. Lower Cretaceous floras of western Canada; Geological Survey of Canada, Memoir 285, p. 80-81 and plates 31, 33, 34, and 36.