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Aberlemnia
''Aberlemnia'' is a genus of extinct vascular plants of the Early Devonian (around ), which consisted of leafless stems with terminal spore-forming organs (sporangia). Fossils found in Scotland were initially described as ''Cooksonia caledonica''.〔 A later review, which included new and more complete fossils from Brazil, showed that the specimens did not fit the circumscription of the genus ''Cooksonia''; accordingly a new genus ''Aberlemnia'' was proposed.〔
==Description==
Fossils from which the genus was first described were found in the Aberlemno quarry, Scotland. Other fossils now assigned to ''Aberlemnia caledonica'' have been found in Wales, Brazil and possibly Bolivia. Plants consisted of smooth leafless stems (axes) up to 1.4 mm wide, decreasing in width at each branching. Specimens branched up to five times, at angles between 25 and 55°, mainly dichotomously, although those from Brazil had some trichotomies. Spore-forming organs or sporangia were borne at the ends of the stems. Individual sporangia varied in shape. Smaller ones were more or less circular in outline, larger ones were kidney-shaped (reniform), up to 2 mm high and 3 mm wide. The difference in shape is interpreted as being due to growth and maturation. To release their spores, the sporangia split into two valves along the border opposite to the stem on which they were attached (i.e. distally).〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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