| Czekanowskiales | |
|---|---|
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| Fossil leaves ofPhoenicopsis angustifolia | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Spermatophytes |
| Clade: | Gymnospermae |
| Order: | †Czekanowskiales Pant, 1957 |
| Genera | |
| |
| Synonyms | |
Leptostrobales Meyen, 1984 | |
Czekanowskiales, also known asLeptostrobales, are an extinct group ofseed plants. Members of the family are distinguished by persistent leaves borne on deciduous short shoots, subtended byscale-like leaves. The leaves are highly dissected (divided into partitions). They likely grew as trees and shrubs.[1] The main ovulate structure of Czekanowskiales,Leptostrobus, consists of bivalved seed-bearing round capsule-like structures arranged along a long axis.[2] The fossil record of Czekanowskiales is largely confined to the Northern Hemisphere, and they inhabited warm-temperate and temperate climates under humid conditions.[3] The oldest possible records of the group are ovulate cones from the LatePermian of Italy,[1] but the group is primarily known from the LateTriassic onwards, and were abundant during theJurassic and EarlyCretaceous. Only a handful of species are known from the Late Cretaceous, confined to the northernRussian Far East, corresponding to the decline of other seed plant groups during the explosive radiation offlowering plants.[4] The affinites of Czekanowskiales to other seed plants are obscure. A close relationship to theGinkgoales has been proposed, based on similar preserved molecular signatures of fossil cuticles,[5] with some authors placing Ginkgoales and Czekanowskiales into the broader grouping Ginkgophyta.[6]