Fossil Araceae from the late Cretaceous of Patagonia, Argentina, with implications on the origin of free-floating aquatic aroids.

JULIETA GALLEGO; GANDOLFO, MARIA; CUNEO, NESTOR RUBEN

REVIEW OF PALAEOBOTANY AND PALYNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 211 p. 78 - 86

0034-6667

Herein, we describe and name a new fossil genus and species, Aquaephyllum auriculatum, and report on the presence of Pandaniidites pollen grains from La Colonia Formation (Maastrichtian, Upper Cretaceous), Patagonia, Argentina. The new fossil taxon is based on leaf impressions and is morphologically similar to members of the family Araceae, subfamily Lemnoideae. The most important morphological characters comprise the adaxial vena- tion with at least eight primary veins, the crenate margin, and the presence of an auricle with a floating function. Phylogenetic analysis places the new taxon in a close relationship within the subfamily Lemnoideae, which also includes the fossils Limnobiophyllum scutatum, Cobbania corrugata, and the extant Pistia stratiotes. Aquaephyllum auriculatum and Pandaniidites are the first fossil record of lemnaceous leaves and the oldest record for Pandaniidites pollen for the Southern Hemisphere respectively. The inclusion of Aquaephyllum and Pandaniidites within a phylogenetic context confirms the previously suggested hypothesis on the existence of close relation- ships between modern Pistia, and the fossils Limnobiophyllum and Cobbania.