Cylostrobus

Cylostrobus Temporal range: Early Triassic PreЄ Є O S D C P T J K Pg N ↓
Cones of Cylostrobus sydneyensis from the Early Triassic Newport Formation near Narrabeen, NSW, Australia.[1]
Scientific classification
Kingdom:	Plantae
Division:	Lycopodiophyta
Class:	Isoetopsida
Order:	Isoetales
Family:	†Pleuromeiaceae
Genus:	Cyclostrobus Retallack 1995
Species
Cylostrobus indicus India Cylostrobus ornatus Argentina Cylostrobus sydneyensis Australia

Leafy apex of Cylostrobus sydneyensis from the Early Triassic Newport Formation near Avalon, NSW

Corm of Cylostrobus sydneyensis from the Early Triassic Newport Formation near Avalon, NSW

Reconstructions of extinct lycopsids Pleuromeia dubia and Cylostrobus sydneyensis (Pleuromeiaceae and Tomiostrobus australis (Isoetaceae) all from the Early Triassic Gosford and Newport Formations of the Sydney Basin, NSW, Australia.

Cylostrobus is genus of Lycopsida most like Pleuromeia, but with very compact and round cones. It is known from the Early Triassic of Australia, coincident with a marked greenhouse spike at the end of the Early Triassic.^[2] The genus Cylostrobus was erected for the compact cone only, in the paleobotanical system of form genera, but these small plants are well enough understood that the name Cylostrobus sydneyensis is used for the whole plant, rather than the old name Pleuromeia longicaulis. Other species of Pleuromeia have attached cones that are less compact and produce different spores.

See also

• Evolution of plants

References

1. Retallack, Gregory J. (1997). "Earliest Triassic origin of Isoetes and quillwort evolutionary radiation". Journal of Paleontology. 7 (3): 500–521.
2. Retallack, Gregory J. (2013). "Permian and Triassic greenhouse crises". Gondwana Research. 24: 90–103. doi:10.1016/j.gr.2012.03.003.