Orestovia
| Orestovia | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||
| Early to Middle Devonian ( Lochkovian to Givetian ) |
||||||||||
| 419.2 to 382.7 million years | ||||||||||
| Locations | ||||||||||
|
||||||||||
| Systematics | ||||||||||
|
||||||||||
| Scientific name | ||||||||||
| Orestovia | ||||||||||
| Ergolskaya | ||||||||||
| Art | ||||||||||
|
||||||||||
Orestovia is a genus of land-dwelling, vegetative organisms from the Devonian of Russia and China . It is in the form of fossil shoot axes in the early and central Devonian coal formations of western Siberia and southern China . The genus and its only species, Orestovia devonica , were first described by Sinaida Jergolskaja in 1936 . Because they have some structures in common with plants , some paleobotanists put them in their immediate relatives. Others suggest it to brown algae or see it as a link between plants and brown algae.
features
Orestovia fossils are bare, unbranched, cutinized axes up to 20 cm long and 26 cm wide that taper towards the tip. Most specimens are preserved as hollow, cuticular sheaths that often have an epidermis- like cellular pattern. Most of the other parts of the tissue, on the other hand, are not fossilized. A delicate strand of tracheid- like tubes with ring-shaped to reticulate thickenings on the inside of the walls runs through the axes . Many tubes contain a central core that is interpreted as resin. There are irregular swellings on the outer side of the axes, which are associated with a secretion function. Small, sunken pores, which are surrounded by several rings of cells or cell-like structures, are distributed over the axes. These structures are interpreted as the stomata apparatus .
In some specimens, spores were found in the cortex of the axes that were 150 to 190 µm in size . On the cuticle were mushrooms found.
Systematics
Orestovia devonica was of Zynaida Vassilyevna Jergolskaja 1936 from the köhlernen Barzas formation West Siberia first described . She chose the generic name in honor of VA Orestov , the specific epithet devonica refers to the age of the fossils. It is partly interpreted as a vascular plant of unknown relationship. Orestovia sees a reconstruction , similar to the recent fern Pilularia globulifera (family Marsileaceae ). with a creeping rhizome in the water and bare, upright axes.
supporting documents
literature
- Valentin Krassilov: Orestovia and the origin of vascular plants . In: Lethaia . tape 14 (3) , 1981, pp. 235-250 , doi : 10.1111 / j.1502-3931.1981.tb01693.x .
- Thomas N. Taylor, Edith L. Taylor, Michael Krings: Paleobotany. The Biology and Evolution of Fossil Plants . Academic Press, Amsterdam & Boston 2009, ISBN 978-0-12-373972-8 .