Publication Date:
2004-10-30
Description:
The emergence of the seed habit in the Middle Paleozoic was a decisive evolutionary breakthrough. Today, seed plants are the most successful plant lineage, with more than 250,000 living species. We have identified a middle Givetian (385 million years ago) seed precursor from Belgium predating the earliest seeds by about 20 million years. Runcaria is a small, radially symmetrical, integumented megasporangium surrounded by a cupule. The megasporangium bears an unopened distal extension protruding above the multilobed integument. This extension is assumed to be involved in anemophilous pollination. Runcaria sheds new light on the sequence of character acquisition leading to the seed.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gerrienne, P -- Meyer-Berthaud, B -- Fairon-Demaret, M -- Streel, M -- Steemans, P -- New York, N.Y. -- Science. 2004 Oct 29;306(5697):856-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Departement de Geologie, B18, Universite de Liege, Sart Tilman, Liege 1, Belgique. p.gerrienne@ulg.ac.be〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15514154" target="_blank"〉PubMed〈/a〉
Keywords:
Belgium
;
*Biological Evolution
;
Fossils
;
Plant Physiological Phenomena
;
Plant Structures/*anatomy & histology
;
Plants/*anatomy & histology/classification
;
Pollen
;
*Seeds
;
Time
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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