Sunday, 6 August 2017

Notonuphar antarctica: A new species of Water Lily from the Eocene of Seymour Island, Antarctica.

Water Lilies, Nymphaeales, are herbaceous aquatic plants found on all continents except Antarctica, but most diverse in the tropics. They are thought to have been one of the earliest groups of Flowering Plants to appear, splitting away from other members of the Angiosperms early in the history of the group, and have a fossil record dating back to the Early Cretaceous.

In a paper published in the journal Plant Systematics and Evolution on 14 June 2017, Else Friis of the Department of Palaeobiology at the Swedish Museum of Natural History, Ari Iglesias of the Instituto de Investigaciones en Biodiversidad y Ambiente, Marcelo Reguero of the Divisio´n Paleontologı´a de Vertebrados at the Universidad Nacional de La Plata and the Instituto Antártico Argentino, and Thomas Mörs, also of the Department of Palaeobiology at the Swedish Museum of Natural History, describe a new species of Water Lily from the Early to Middle Eocene of Seymour Island, Antarctica.

The new species is named Notonuphar antarctica, where 'Notonuphar' means 'southern-Nuphar' (Nuphar being a modern genus from the Northern Hemisphere which the new genus resembles) and antarctica refers to the location where it was found. The species is described from a series of seeds and seed fragments extracted from sediments by dry sieving. These are coalified on the outside, with a calcified inner core comprised of the mesotesta, endotesta, tegmen and the inner seed tissues.

Notonuphar antarctica, from the Eocene of Seymour Island, Antarctica; synchrotron radiation-based X-ray tomographic microscopy volume renderings of seeds. (a) Holotype; lateral view of seed showing outer smooth surface of exotesta and germination; hilum (hi) and micropyle (mi) are close to each other on the germination cap. (b), (c) Lateral views of seed with exotesta partly broken off exposing the inner calcified core lined by mesotesta and tegmen; note the distinct raphe on the inner core. (d) Apical view of holotype showing germination cap with closely spaced hilum (hi) and micropyle (mi). (e) Apical view of seed with part of exotesta and germination cap preserved; note tall and thick-walled cells exotesta and the thin layer of mesotesta between exotesta and tegmen. (f), (g) Volume renderings cut through the micropylar (mi) and hilar (hi) area of seed shown in (e) in angles perpendicular to each other; mesotesta is thicker close to the micropyle. (h), (i) Volume renderings transversely cut through the micropylar (mi) and hilar (hi) area of seed shown in (e) at two different levels, (h) close to the apex and (i) further down; note narrow zone of exotestal cells (asterisk) between micropyle and hilum/raphe (h cut at orthoslice xy0300; i cut at orthoslice xy0510). Scale bars 1 mm (a–c), 0.5 mm (d–i). Friis et al. (2017).

See also...

http://sciencythoughts.blogspot.co.uk/2016/08/euanthus-panii-flower-from-middle-late.htmlhttp://sciencythoughts.blogspot.co.uk/2016/04/juraherba-bodae-herbaceous-angiosperm.html
http://sciencythoughts.blogspot.co.uk/2016/03/mahonia-mioasiatica-fossil-leaves-from.htmlhttp://sciencythoughts.blogspot.co.uk/2015/12/prunus-kunmingensis-peaches-from-late.html
http://sciencythoughts.blogspot.co.uk/2015/01/the-antarctic-summer-monsoon.htmlhttp://sciencythoughts.blogspot.co.uk/2014/11/supplejack-leaves-from-early-eocene-of.html
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