Lauraceous fossil woods from the early Eocene of Laguna del Hunco, Argentine Patagonia

Abstract

Two silicified fossil woods are identified as a new species of Laurinoxylon from the Huitrera Formation at Laguna del Hunco in the Chubut Province of Argentina. Supporting characters include the absence of growth ring boundaries, vessels solitary or in short radial multiples, sim­ple and scalariform perforation plates, alternate intervessel pitting, scalariform vessel-ray pits, scarce axial parenchyma, septate fibres, rays usually one to four cells wide, and idioblasts com­monly associated with rays and rarely with the axial parenchyma. The fossil woods resemblemembers of the Perseae-Cinnamomeae-Laureae clade but do not closely match any extant genus; they therefore probably represent an extinct lineage. Although lauraceous woods are known from other Palaeocene and Eocene floras in Patagonia, the presence of the family at Laguna del Hunco was previously based only on leaf compressions without preserved cuticulardetails. Our new record confirms the occurrence of Lauraceae in the diverse Laguna del Hunco flora, which contains many genera associated with extant rainforest floras.