Late Cretaceous Aquatic Plant World in Patagonia, Argentina

• DOI: 10.1371/journal.pone.0104749
• Publication Date: 2014-08-22T19:17:36Z
• Authors: N. Rubén Cúneo; María A. Gandolfo; María C. Zamaloa; Elizabeth Hermsen
• Keywords: Azolla; Terrestrial plant; Paleoecology; Biota

In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The Formation is a geological unit deposited during Maastrichtian-Danian transgressive episode of South Atlantic Ocean. This event resulted in deposition series fine-grained sediments associated with lagoon systems occurring along irregular coastal plains northern Patagonia. These deposits preserved diverse biota, including terrestrial plants animals. macrophytes can be broadly divided into two groups: free-floating rooted, latter emergent or floating leaves. Free-floating include ferns Salviniaceae (Azolla Paleoazolla) monocot (Araceae). Floating microphytes green algae (Botryoccocus, Pediastrum Zygnemataceae). Among rooted components, marsileaceous water (including Regnellidium an extinct form) eudicot angiosperm Nelumbo (Nelumbonaceae) are dominant groups. Terrestrial vegetation surrounding lagoons monocots (palms Typhaceae), affinities to Dicksoniaceae, conifers, dicots. A reconstruction paleocommuniy provided distribution fossils freshwater horizon within Formation. contribution constitutes first habitat for southern America.