The first record of Lauraceae fossil woods from the Cretaceous Puerto Yeruá Formation of eastern Argentina and palaeobiogeographic implications

Abstract

In this paper, a new species of fossil wood, Paraperseoxylon septatum sp. nov. (Lauraceae), from the Cretaceous of Puerto Yeruá Formation, is described. The fossil wood herein studied has features of the Lauraceae family, and particularly resembles the extant genus Persea Mill. The possible climatic conditions of the Puerto Yerúa Formation were inferred using the Vulnerability Index, Mesomorphy ratios and the Taxon Independent Approach of the anatomical features present in the fossil wood described, suggesting a warm and humid to seasonally dry context. This material is the first record known from the Cretaceous of Northeastern Argentina and the earliest occurrence in the Southern Hemisphere of a fossil taxon with feature closest to Persea, and clearly establishes the presence of Lauraceae in Northeastern Argentina during the Cretaceous. Nowadays the genus Persea has a tropical and subtropical disjunct distribution in the Americas, Asia, and the Canary Islands. The present study provides information pertinent to understanding its phylogenetic context and biogeographic history.