Jump to content

Pliocene flora of Frankfurt am Main

From Wikipedia, the free encyclopedia

It is suggested a late Pliocene age (Reuverian) for this flora. Palynofloras from drill cores in the surroundings of Frankfurt am Main and Hanau also suggests a late Pliocene age. The Pliocene flora of Frankfurt am Main described by Karl Mädler during the first half of the twentieth century is a key flora for the European Pliocene.

In total 16 gymnosperm species in 15 genera and 73 angiosperm species (of which 15 could not be assigned to a genus) in 40 genera are recognised in the leaf record. Main characteristics of the flora are the high diversity of conifers, deciduous angiosperm genera such as Eucommia, Magnolia and Sassafras, a diverse assemblage of exclusively deciduous Fagaceae, including six species of oaks, the high diversity of Rosaceae, whereas evergreen taxa are shrubs typical of the understorey as Buxus, Ilex, Pachysandra, Prunus lusitanica and Viscum.

These features indicate cool temperate climatic conditions comparable to present-day Lugano in southern Switzerland. The flora shows a strong biogeographic link with East Asia, surprisingly high levels of Pliocene endemisms and that the European flora was more diverse in woody species shortly before the onset of the major Pleistocene glaciations than today. The early part of the Pliocene (5.3–3.6 Ma) was characterised by warm conditions (ca. 3 °C higher global surface temperatures) and higher sea levels (10–20 m) and slightly higher CO2 concentrations.

During the second part of the Pliocene, gradual cooling culminated in a significant intensification of northern hemispheric glaciation at ca. 2.75 Ma. Despite this, many exotic taxa persisted as relicts from older epochs and modern diversity patterns of trees and shrubs across the Northern Hemisphere were established only during and after the major Pleistocene glaciations.[1][2][3]

History of the fossil findings

[edit]

Fossil plant remains had been discovered in the excavation pit of the Höchst lock in 1884, a sandy clay layer, many more fossil seeds, fruits and leaves were uncovered in 1885 during the construction of the Frankfurt water clarifier near Niederrad. The works on these plant fossils were edited by GEYLER & KINKELIN and their results were published in the 15th volume of the Treatises of the Senckenbergische Naturforschende Gesellschaft in 1887. The plant fossils are kept at the Naturmuseum Senckenberg in Frankfurt am Main.[4]

Geography

[edit]

The fossil leaves comprising the flora have been recovered in Niederrad which is a quarter of Frankfurt am Main, Germany. It is part of the Ortsbezirk Süd and is subdivided into the Stadtbezirke Niederrad-Nord, Niederrad-Süd and the new Niederrad-West. Niederrad is bordered in the north by the River Main, in the west by the A5 Autobahn, in the south by the Main Railway and Flughafenstraße, and in the east by the former Niederrad Racecourse, Kennedyallee and the Main-Neckar Railway.

[edit]

Fossil plant species so far described from the deposits

[edit]

Gymnosperms

[edit]

Ginkgoaceae

  • Metasequoia langsdorfii, synonym: Sequoia langsdorfii.
  • Abies alba fossilis synonym Abies pectinata fossilis, a needle and one seed cone.
  • Abies sclereidea, two needle fragments.

Angiosperms, dicots

[edit]
  • Viscum pliozänicum, leaf and epidermal preparation.
  • Buxus pliocaenica, one entire leaf and a leafy shot.
  • Alnus gaudinii, (complete and incomplete leaves), the nearest living relative for this fossil species is the Caucasian alder, Alnus subcordata that differs from the fossil species by slightly wider leaves.
  • Celtis trachytica, (incomplete leaf).
  • Zelkova zelkovifolia, complete leaves.
  • Populus balsamoides, a complete leaf.
  • Populus canescentoides , complete leaves.
  • Populus gregorii, incomplete leaves.
  • Populus populina, complete and incomplete leaves.
  • Salix lavateri , complete and incomplete leaves.
  • Malus sp., a complete leaf with serrulate margin.
  • Spiraea trichocarpa aff., an entire leaf.
  • Gleditsia pliocaenica, the modern Gleditsia caspica Desfontaines produces similar foliage and might be the closest extant relative of the fossil taxon, but differs from Gleditsia caspica in broader asymmetrically ovate leaflets and a distinctly crenulate lamina.
  • Craigia lobata, a complete leaf.
  • Tilia? sp., isolated bracts.
  • Eucommia europaea
  • Eucommia szaferi, one leaf and one epidermal preparation.
  • Styrax obovatum, two seeds.
  • Stewartia europaea synonym Stuartia europaea, one fruitlet.
  • Ilex aquifolium, one entire leaf and several leaf remains.
  • Ilex geissertii, an abaxial cuticle.
  • Fraxinus angusta (abaxial cuticle with peltate trichomes).

Angiosperms, monocots

[edit]


References

[edit]
  1. ^ The Pliocene flora of Frankfurt am Main, Germany: taxonomy, palaeoenvironments and biogeographic affinities by Zlatko Kvaček, Vasilis Teodoridis & Thomas Denk – Palaeobiodiversity and Palaeoenvironments, pages 647–703 (2020) – Springer Link – https://doi.org/10.1007/s12549-019-00391-6
  2. ^ Mädler, Karl. Die pliozäne flora von Frankfurt am main. Vol. 446. Alexander Doweld, 1939.
  3. ^ On the fossil history of Pseudotsuga Carr. (Pinaceae) in Europe by Lutz Kunzmann – Palaeobiodiversity and Palaeoenvironments 94(2):39 3–409, June 2014 – Senckenberg Natural History Collections – https://doi.org/10.1007/s12549-014-0156-x
  4. ^ Oberpliocän-Flora aus den Baugruben des Klärbeckens bei Niederrad und Schleuse bei Höchst a M. T. Geyler F. Kinkelin. (Frankfort, 1887).