Apocalamitaceae (Sphenophyta) triásicas de la Formación Paramillo, Agua de la Zorra, provincia de Mendoza, Argentina

Abstract

This paper is part of a systematic study of the fossil flora from the Paramillo Fonnation (Agua de la Zorra, Uspallata, Mendoza province, Argentina). In this contribution the Apocalamitaceae (Sphenophyta) are analyzed. The taxa identified are: Neocalamiies carrerei (Zeiller) Halle, aff. Nododcndron suberosunt Artabe and Zarnuner, and a new species of Neocalumostacuus. The latter, N. arrondoi n. sp., shows a unique combination of features. The stem of Neocalamites and nodal diaphragm of Nododcudron found in close association with the reproductive structure Neoculamostacltus indicate that Ncocalmnitcs, Nododendron and Neocalamostachue were probably based on parts of individuals of a single taxon. This paleocommunity of Apocalamitaceae was herbaceous-arbustive, with one stratum and only one characteristic species with hydrophytic adaptations. The age of the Paramillo Formation is regarded as early Middle Triassic - early Upper Triassic.