Ferugliocladaceae
| Ferugliocladaceae | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||||
| Lower Permian | ||||||||||||
| 285 to 270 million years | ||||||||||||
| Locations | ||||||||||||
|
South America |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Ferugliocladaceae | ||||||||||||
| Archangelsky & Cúneo |
The Ferugliocladaceae are an extinct family of conifers from the order of the Voltziales .
features
The representatives are very branched out. The branching is irregular and radial. The shoot axes carry small, about 1 cm long, uniform, lanceolate leaves in a spiral arrangement. The leaves have a single vascular bundle .
The seed- and pollen-forming cones sit at the branch ends and are egg-shaped. The seed cones consist of a cone axis with spirally arranged bracts and orthotropic (upright), platyspermic (flattened) ovules that are apparently or actually free. The seeds reach their maximum size while they are on the cone.
No sterile scales can be seen on the fossils of the female cones. One possible reason for this is that sterile and fertile scales have fused into the stalk of the ovule and are no longer recognizable as such. This would mean that the family ancestor, like that of other early conifers, had flattened sterile and fertile scales. Another possibility is that the axillary ovules developed from an ancestor with axillary, orthotropic ovules.
The pollen-forming cones consist of a cone axis on which the microsporophylls are in a spiral arrangement . The pollen is monosaccat (have an air sac) and is of the Cannanoropollis type .
Systematics
The Ferugliocladaceae family was established by Archangelsky and Cúneo in 1987. Their representatives are limited to Gondwana . In 1988 Clement-Westerhof named the following genera and species:
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Ferugliocladus , natural genus by bifide micropyle in
- Ferugliocladus riojanum from the Gangamopteris zone of Argentina
- Ferugliocladus patagonicus
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Ugartecladus , natural genus, differs from Ferugliocladus in that the ovules do not have bifid micropyle.
- Ugartecladus genoensis from the Gangamopteris zone of Argentina
- Eucerospermum : genus for isolated seeds.
Genoites patagonica is described by Taylor et al. (2009) interpreted it as a possible precursor of the Ferugliocladaceae. The twigs have bifid leaves arranged in a spiral. There are stalked, orthotropic ovules in the axils of some leaves. The Ferugliocladaceae cone would be derived from a reduction in this system.
The Ferugliocladaceae are mostly viewed as an early side branch of the Voltziales . Cladistic analyzes reveal a position at the base of the Coniferopsida and thus also the Voltcials.
supporting documents
- Thomas N. Taylor, Edith L. Taylor, Michael Krings: Paleobotany. The Biology and Evolution of Fossil Plants . Second Edition, Academic Press 2009, pp. 823ff., ISBN 978-0-12-373972-8
- Johanna A. Clement-Westerhof: Morphology and Phylogeny of Paleozoic Conifers . In: Charles B. Beck (Ed.): Origin and Evolution of Gymnosperms . Columbia University Press, New York 1988, ISBN 0-231-06358-X , pp. 298-337, especially pp. 326f.
Individual evidence
- ^ Gar W. Rothwell, Gene Mapes, Genaro R. Hernandez-Castillo: Hanskerpia gen. Nov. and phylogenetic relationships among the most ancient conifers (Voltziales) . Taxon, Vol. 54, 2005, pp. 733-750.