Pecopteris
| Pecopteris | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Pecopteris villosa from the Mazon Creek Formation |
||||||||||||
| Temporal occurrence | ||||||||||||
| Lower Carboniferous to Perm | ||||||||||||
| 359 to 251 million years | ||||||||||||
| Locations | ||||||||||||
|
worldwide |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Pecopteris | ||||||||||||
| Brongn. | ||||||||||||
Pecopteris is a genus of plants in which leaf fossils are grouped together ( Morphotaxon ). They are widespread worldwide and occur frequently in the Carboniferous and Permian .
features
Pecopteris are pinnate leaves. The leaf leaflets are usually small and separate from each other. They sit on the rachis with their entire width . Their edges are often parallel or almost parallel. A single vascular bundle enters the feathers and extends almost to its tip. The end of the leaflet is rounded. The lateral nerves are straight to slightly curved and bifurcated simply or near the leaf margin.
Systematic dissemination
Pecopteris leaves are found on the Carboniferous fern genus Psaronius from the Marattiopsida group . Furthermore with some Polypodiopsida and with at least one seed fern .
Others
About 300 species are known. The pecopterids were mostly tree-shaped in their growth form. The leaves have pinnate veins. The corresponding trunks , if they are preserved in structure, are described as Psaronius and in superficial preservation as Caulopteris . In addition, the parent species Megaphyton , Hagiophyton and Artisophyton could also belong, but this has not yet been clearly shown. Many known Aphlebia species (protective leaves ) can also be assigned to this genus.
Fertile material is divided into the following fructification types: Senftenbergia , Scolecopteris , Ptychocarpus , Zeilleria , Asterotheca , Acitheca , Dactylotheca . In the literature there are sometimes different assessments of the description of the sporangia type Scolecopteris , many authors (Laveine, Josten et al.) Believe that Asterotheca and Scolecopteris are the same. But M. Barthel 2009 gives an assessment of this problem, so that only Pecopteris sternbergi belongs to the sporangia type Asterotheca . He is referring to Stur (1883), who at the time correctly assigned everything through his studies in this area, but was not recognized by his international colleagues.
For a long time, relatively few Pecopteris species (Gutbier 1843, 1849 and Geinitz 1855, Daber 1955) were described from the Saxon coal mining area of Zwickau-Oelsnitz ; only Schultka (2009) discovered many new ones in the collections of the local museums that were previously unknown for Zwickau-Oelsnitz Pecopteris types and described them for the first time. As with Daber 2002, a special connection to the Saarland district could be established. Many species previously described only from there could now also be detected here, although in Zwickau-Oelsnitz only the two sporangia types Senftenbergia and Scolecopteris were found. However, since the corresponding sporangia type is known from other localities for certain Pecopteris species, Ptychocarpus and Acitheca fructifications should also be found, which is still not the case today.
literature
- M. Barthel: Plant groups and vegetation units of the Manebach formation. In: Contributions to the geology of Thuringia. Volume 8, Jena 2001, pp. 93-123.
Individual evidence
- ^ A b c Thomas N. Taylor, Edith L. Taylor, Michael Krings: Paleobotany. The Biology and Evolution of Fossil Plants. 2nd Edition. Academic Press, Amsterdam et al. 2009, ISBN 978-0-12-373972-8 , pp. 679f.
