Nilssonia (plant)

Nilssonia; Temporal range: Triassic–Late Cretaceous PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Plantae
(unranked):	Spermatophyta
Division:	Cycadophyta
Order:	Nilssoniales
Genus:	Nilssonia; (Brongniart), 1825.
Species
	N. brevis (Type species); N. compta; N. eskensis; N. gristhorpensis; N. kendalli; N. lunzensis; N. neuberi; N. tenuicaulis; N. tenuinervis;

Nilssonia is a genus of fossil foliage traditionally assigned to the Cycadophyta either in Cycadales or their own order Nilssoniales, though the relationships of this genus with the cycadales have been put into question on chemical grounds.^[2] Fossils of Nilssonia are found in Triassic, Jurassic and Cretaceous-aged terrestrial strata of East Asia, Australia, North and South America, and Europe.^[3]^[4]^[5]

Description

Nilssonia leaves can have entire margins, irregularly dissected margins or clearly divided leaflets. The lamina or the leaflets are attached to the midrib or rachis on the 'upper' (adaxial) side of the leaf. Parallel veins exit the midrib, with no fusion of veins.

Location of palaeontological sites

Australia
In Paleorrota geopark in Brazil. Upper Triassic period, the Santa Maria Formation.^[6]
China
United Kingdom, the Cloughton Formation (Jurassic period).
United States

References

^ Early Cretaceous macrofloras of Western Australia^{[full citation needed]}
^ Vajda, Vivi; Pucetaite, Milda; McLoughlin, Stephen; Engdahl, Anders; Heimdal, Jimmy; Uvdal, Per (August 2017). "Molecular signatures of fossil leaves provide unexpected new evidence for extinct plant relationships". Nature Ecology & Evolution. 1 (8): 1093–1099. doi:10.1038/s41559-017-0224-5. ISSN 2397-334X.
^ Pott, Christian; Kerp, Hans; Krings, Michael (2007). "Morphology and epidermal anatomy of Nilssonia (cycadalean foliage) from the Upper Triassic of Lunz (Lower Austria)". Review of Palaeobotany and Palynology. 143 (3–4): 197–217. doi:10.1016/j.revpalbo.2006.07.007.
^ Cleal, Christopher J; Rees, P. Mcallister; Zijlstra, Gea; Cantrill, David J (2006). "A Clarification of the Type of Nilssoniopteris Nathorst (Fossil Gymnospermophyta, Bennettitales)". Taxon. 55 (1): 219–22. doi:10.2307/25065546. hdl:1874/307500. JSTOR 25065546.
^ "The Cycads, Cycadeoids (Bennettitales) and Ginkgophytes". Archived from the original on 2013-09-21. Retrieved 2013-07-12.
^ Passo das Tropas, Santa Maria, RS. Marco bioestratigráfico triássico na evolução paleoflorística do Gondwana na Bacia do Paraná^{[full citation needed]}

[botanica1-1] Early Cretaceous macrofloras of Western Australia^{[full citation needed]}

[2] Vajda, Vivi; Pucetaite, Milda; McLoughlin, Stephen; Engdahl, Anders; Heimdal, Jimmy; Uvdal, Per (August 2017). "Molecular signatures of fossil leaves provide unexpected new evidence for extinct plant relationships". Nature Ecology & Evolution. 1 (8): 1093–1099. doi:10.1038/s41559-017-0224-5. ISSN 2397-334X.

[botanica2-3] Pott, Christian; Kerp, Hans; Krings, Michael (2007). "Morphology and epidermal anatomy of Nilssonia (cycadalean foliage) from the Upper Triassic of Lunz (Lower Austria)". Review of Palaeobotany and Palynology. 143 (3–4): 197–217. doi:10.1016/j.revpalbo.2006.07.007.

[botanica3-4] Cleal, Christopher J; Rees, P. Mcallister; Zijlstra, Gea; Cantrill, David J (2006). "A Clarification of the Type of Nilssoniopteris Nathorst (Fossil Gymnospermophyta, Bennettitales)". Taxon. 55 (1): 219–22. doi:10.2307/25065546. hdl:1874/307500. JSTOR 25065546.

[botanica4-5] "The Cycads, Cycadeoids (Bennettitales) and Ginkgophytes". Archived from the original on 2013-09-21. Retrieved 2013-07-12.

[botanica-6] Passo das Tropas, Santa Maria, RS. Marco bioestratigráfico triássico na evolução paleoflorística do Gondwana na Bacia do Paraná^{[full citation needed]}

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