A new specimen of Millerocaulis (Osmundales: Osmundaceae) from the Cerro Negro Formation (Lower Cretaceous), Antarctica

• Autores: Ezequiel Vera
• Localización: Revista del Museo Argentino de Ciencias Naturales, ISSN-e 1853-0400, ISSN 1514-5158, Vol. 12, Nº. 1, 2010, págs. 41-46
• Idioma: español
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• Resumen

  • A new petrified stem of Millerocaulis Erasmus ex Tidwell emend. Vera, collected in the Aptian CerroNegro Formation outcrops of Livingston Island (Antarctica), is described in detail. This specimen is probablyconspecific with Millerocaulis australis (Vera), from the same unit, but it is smaller than the holotype and onlyknown specimen of the latter species. Furthermore, differences between several characteristics of both specimensare observed. A discussion based on biological aspects of this group of plants is given, taking into accountthe ontogenetic variability. A conservative referral of the new specimen to M. australis is preferred over theproposal of a new morphotaxon for the inclusion of the new materials.