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Posts mit dem Label paleobotany werden angezeigt. Alle Posts anzeigen

Samstag, 9. Februar 2013

Madygen bryophytes and lycopsids


Moisan, P., S. Voigt, J. W. Schneider & H. Kerp. 2012. New fossil bryophytes from the Triassic Madygen Lagerstätte (SW Kyrgyzstan). Review of Palaeobotany and Palynology 187:29–37. [Abstract]

Recent paper on liverworts and leafy mosses from the Madygen Formation. Adds some new aspects about the Madygen flora which is known for its diversity of seed ferns, lycopsids, horsetails, and cycadophytes whereas (unambiguous) fossils of non-vascular plants, some of them occurring densely packed in shallow lacustrine sediments (and possibly represent submerged plants of the lake margin), have been described for the first time by Moisan and colleagues.

Moisan, P. & S. Voigt. 2013, in press. Lycopsids from the Madygen Lagerstätte (Middle to Late Triassic, Kyrgyzstan, Central Asia). Review of Palaeobotany and Palynology. [Abstract]

Revision of the Madygen lycopsids and of the problematic "Longisquama-appendage-like" foliage Mesenteriophyllum based on materials excavated between 2006 and 2009 whose macromorphological and microscopic epidermal features were studied. Originally described by Sixtel (1961) as a new genus of gymnosperms, Mesenteriophyllum-like plants are now found to belong to different higher lycopsid taxa (Pleuromeiales, Isoetales).

Montag, 9. Juli 2012

Insect-plant interaction in the Madygen forest

Philippe Moisan, who defended his Ph.D. thesis on floral remains from the Madygen Formation earlier this year, is main author of a recently published paper on ovipostion damage:

Moisan, P., C. C. Labandeira, N. A. Matushkina, T. Wappler, S. Voigt, and H. Kerp (2012): Lycopsid–arthropod associations and odonatopteran oviposition on Triassic herbaceous Isoetites. Palaeogeography, Palaeoclimatology, Palaeoecology 344–345: 6–15. [Link to abstract]

Describes an oviposition damage pattern typical for dragonflies on the quillwort Isoetites which is an unusual thing because lycopsids were not yet known to be hosts of dragonfly egg-laying.

Sonntag, 16. Januar 2011

New paper on cycadophytes from Madygen

Moisan, P., S. Voigt, C. Pott, M. Buchwitz, J. Schneider, and H. Kerp. in press. Cycadalean and bennettitalean foliage from the Triassic Madygen Lagerstätte (SW Kyrgyzstan, Central Asia). Review of Palaeobotany and Palynology. [DOI:10.1016/j.revpalbo.2010.11.008]

Philippe Moisan who is doing his Ph.D. in Münster (with paleobotanist Hans Kerp as his supervisor) studies the flora of the Triassic Madygen Fm. In his first paper on that issue he introduces cycadophyte finds collected between 2005 and 2009.

Many of the studied the specimen come from the same succession and locality as Madygenerpeton (there is also a small sketch of the sedimentary profile, see Fig. 2).

One thing I learned from this study was that so-called "xeromorphic features", i.e. plant features that are usually the consequence of an adaptation to aridity, cannot only occur in xerophytes, i.e. in plants adapted to dry environments, but (for other reasons) in hygrophytic and halophytic plants as well.

Indications for aridity, such as desiccation crack horizons or or seasonally drying-out ponds and rivers or wide-spread red bed sediments are lacking in Madygen. Thus, according to Philippe's interpretation, "xeromorphism" in Madygen plants probably served other purposes than the xeromorphism of xerophytes (e.g. "self-cleaning of the leaf surface, regulation of excessive radiation and leaf temperature, mechanical defense against phytophagous insects").