  The Middle-Devonian proto-ovule Runcaria heinzelinii Stockmans 1968Gerrienne, Philippe  ; ; Fairon-Demaret, Muriel et alConference (2005) Detailed reference viewed: 16 (0 ULg) Runcaria, a middle Devonian seed plant precursorGerrienne, Philippe ; ; Fairon-Demaret, Muriel et alin Science (2004), 306(5697), 856-858 The emergence of the seed habit in the Middle Pateozoic was a decisive evolutionary breakthrough. Today, seed plants are the most successful plant lineage, with more than 250,000 living species. We have ... [more ▼] The emergence of the seed habit in the Middle Pateozoic 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. [less ▲] Detailed reference viewed: 56 (18 ULg)The plant Leclercqia (Lycopsida) in Gondwana: implications for reconstructing Middle Devonian palaeogeography; Fairon-Demaret, Muriel ; Steemans, Philippe et alin Geological Magazine (2003), 140(2), 119-130 Abundant and well-preserved material of the ligulate lycopsid genus Leclercqia is reported from a new Middle Devonian locality in northeastern Queensland (Australia). The plants occur in a chert horizon ... [more ▼] Abundant and well-preserved material of the ligulate lycopsid genus Leclercqia is reported from a new Middle Devonian locality in northeastern Queensland (Australia). The plants occur in a chert horizon in the Storm Hill Sandstone of the Dosey-Craigie Platform. Lithological data and conodont analyses combined with information from in situ spores provide an age for the plant levels ranging from Eifelian, possibly Middle Eifelian, to Early Givetian. Plant taxonomic identification is based on vegetative and fertile stems that display both external morphology and anatomy. This material represents the best documented occurrence of Leclercqia outside Laurussia and possibly the earliest in Gondwana; it provides evidence that colonization of Gondwana by the species L. complexa was contemporaneous to that of Siberia and Kazakhstan. Analysis of the distribution patterns of L. complexa suggests that it was adapted to a wide range of environments, but within certain limits which we hypothesize to be those of a climatic belt. Such considerations support previous studies using other biological data, such as faunas and palynomorphs, for reconstructing Devonian palaeogeography. They favour a close proximity of Laurussia and Gondwana rather than the occurrence of a wide ocean separating the two palaeocontinents in Middle Devonian times. [less ▲] Detailed reference viewed: 36 (4 ULg)The Middle Devonian plant Leclercqia (Lycopsida) in eastern Gondwana; Fairon-Demaret, Muriel ; Steemans, Philippe et alConference (2002) Detailed reference viewed: 3 (0 ULg)Les plantes éodévoniennes d'Azrou (Maroc central) et leurs implications paléogéographiquesGerrienne, Philippe ; Fairon-Demaret, Muriel ; et alConference (1998) Detailed reference viewed: 5 (1 ULg)Lower Devonian flora from Morocco and its palaeogeographical implicationsGerrienne, Philippe ; Fairon-Demaret, Muriel ; et alConference (1997) Detailed reference viewed: 1 (0 ULg) |
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