Callistophytales
| Callistophytales Temporal range:
| |
|---|---|
| |
| Reconstruction of the plant Callospermarion pusillum (permineralized ovules), Idanothekion callistophytoides (pollen organ), Dicksonites pluckenetii (leaves), Callistophyton poroxyloides (stem), and Vesicaspora shaubergeri (pollen) from the Pennsylvanian Calhoun Formation of Berryville, Illinois.[1] | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Division: | †Pteridospermatophyta |
| Class: | †Lyginopteridopsida (?) |
| Order: | †Callistophytales G.W.Rothwell 1981, emend. 1982 |
| Families | |
Callistophytales is an extinct order of
pinnate
leaves superficially similar to modern ferns.
Callistophytales in particular are characterized by their reproductive anatomy. The ovules are bilaterally symmetrical and non-cupulate, attaching to the underside of
pteridosperms
, some of which they seem to have out-competed and replaced in the "coal swamp" vegetation during Late Pennsylvanian and Permian times.
Callistophytales are occasionally classified within the class
Lyginopteridopsida, alongside the order Lyginopteridales. This proposal is controversial due to the apparent sophistication of the ovules and pollen.[3]
There are nevertheless many other characters that suggest that the Callistophytales is derived from a more primitive lyginopterdalean-like ancestor, including the presence of a lagenostome at the apex of the nucellus, the general structure of the pollen organs, and the overall morphology of the vegetative structures.
Two families have been recognised: the Callistophytaceae, known mainly from the Carboniferous floras of Euramerica; and the Emplectopteridaceae, known mainly from the Permian floras of China and adjacent areas.
References
- ^ Retallack, G.J.; Dilcher, D.L. (1988). "Reconstructions of selected seed ferns". Missouri Botanical Garden Annals. 75: 1010–1057.
- ^ Anderson J. M.; Anderson H. M.; Cleal C. J. (2007). "Brief history of the gymnosperms: classification, biodiversity, phytogeography and ecology". Strelitzia. 20: 1–279.
 | This article related to a Carboniferous plant is a stub. You can help Wikipedia by expanding it. |
 | This article related to a Permian plant is a stub. You can help Wikipedia by expanding it. |