Thyrsopteris

Thyrsopteris Temporal range: Cenomanian–Recent PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Polypodiophyta
Class:	Polypodiopsida
Order:	Cyatheales
Family:	Thyrsopteridaceae C.Presl
Genus:	Thyrsopteris Kunze
Species:	T. elegans
Binomial name
Thyrsopteris elegans Kunze
Synonyms
Family: Thyrsopterideae (Fée) Pfeiffer Thyrsopteridoideae B.K.Nayar Genus: ChontaMolina 1782 PaniculariaColla 1836 Species: Dicksonia elegans(Kunze 1834) Mettenius 1861 Panicularia berteriColla 1836

Thyrsopteris is a genus of tree fern. It contains a single living species, Thyrsopteris elegans, endemic to the Juan Fernandez Archipelago off the coast of Chile. Thyrsopteris is the only genus in the family Thyrsopteridaceae in the Pteridophyte Phylogeny Group classification of 2016 (PPG I). ^[1] Alternatively, the genus may be placed in the subfamily Thyrsopteridoideae of a more broadly defined family Cyatheaceae, ^[2] the family placement used in Plants of the World Online as of November 2019 ^[update] . ^[3] The oldest records of the genus are the species Thyrsopteris cretacea and Thyrsopteris cyathindusia which were described from the Burmese amber of Myanmar, dating to the Cenomanian of the Cretaceous period, around 99 million years ago. ^{[4] [5]} Other fossil species include Thyrsopteris antiqua from the Upper Cretaceous of Chile and Thyrsopteris shenii from the Paleogene of King George Island, Antarctica ^{[6] [5]} A thyrsopterid rachis is also known from the Upper Cretaceous of Japan. ^[7]

Description

T. elegans is perhaps unique in having fronds which are quadripinnate or even pentapinnate (leaflets are the fifth order of branching). ^{[8] [ clarification needed ]}

References

1. PPG I (2016). "A community-derived classification for extant lycophytes and ferns". Journal of Systematics and Evolution. 54 (6): 563–603. doi: 10.1111/jse.12229 . S2CID   39980610.
2. Christenhusz, Maarten J.M. & Chase, Mark W. (2014). "Trends and concepts in fern classification". Annals of Botany. 113 (9): 571–594. doi:10.1093/aob/mct299. PMC   3936591 . PMID   24532607.
3. "Thyrsopteris Kunze". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2019-11-23.
4. Li, Chunxiang; Moran, Robbin C.; Ma, Junye; Wang, Bo; Hao, Jiasheng; Yang, Qun (2020-01-01). "A mid-Cretaceous tree fern of Thyrsopteridaceae (Cyatheales) preserved in Myanmar amber" . Cretaceous Research. Non-marine and Marine Cretaceous in China: Stratigraphy, Palaeobiogeography, Palaeoecology and Palaeoclimates. 105: 104050. Bibcode:2020CrRes.10504050L. doi:10.1016/j.cretres.2019.01.002. ISSN   0195-6671. S2CID   134746241.
5. Zhang, Hong-Rui; Shi, Chao; Long, Xiao-Xuan; Feng, Qi; Cai, Hao-Hong; Lü, Ying-Tao; Wang, Shuo (2021-09-16). "A new fossil record of Thyrsopteridaceae (Cyatheales) from the mid-Cretaceous amber of Myanmar" . Palaeoworld. 31 (3): 478–484. doi:10.1016/j.palwor.2021.09.002. ISSN   1871-174X. S2CID   240519538.
6. Zhaonai, Li; Xiaohan, Liu; Ruxiang, Shang (2009-05-29). "The Characteristics and Mechanism of Island-Arc Volcanism on the Central and Southern Fildes Peninsula, King George Island, Antarctica" . Acta Geologica Sinica - English Edition. 5 (1): 39–57. doi:10.1111/j.1755-6724.1992.mp5001003.x. ISSN   1000-9515.
7. Nishida, Harufumi; Nishida, Makoto (September 1979). "Thyrsopterorachis, gen. nov., a tree fern rachis from the upper cretaceous of Hokkaido, Japan" . The Botanical Magazine Tokyo. 92 (3): 187–195. doi:10.1007/BF02497930. ISSN   0006-808X. S2CID   12138701.
8. Large, Mark F.; Braggins, John E. (2004). Tree Ferns. Portland, Oregon: Timber Press. p. 306. ISBN   0-88192-630-2.