Runcaria, a Middle Devonian Seed Plant Precursor

  title={Runcaria, a Middle Devonian Seed Plant Precursor},
  author={Philippe Gerrienne and Brigitte Meyer-Berthaud and Muriel Fairon‐Demaret and Maurice Streel and Philippe Steemans},
  pages={856 - 858}
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… 
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