TWO NEW REPORTS OF ANCIENT RAINFOREST TREES FROM THE AZUERO PENINSULA, PANAMA

Abstract

Silicified woods are abundant on the Azuero Peninsula in Panama, but only five publications document Oligocene–Miocene occurrences in the region. In this article, we present two new fossil wood types from the Azuero Peninsula. The first one shares traits diagnostic of Prioria (Fabaceae). Characters supporting this identification include alternate minute intervessel pitting, vessel-ray parenchyma pitting similar to intervessel pits in size and shape, axial canals that are diffuse and in short lines, and rays that are 1–3 cells wide. Prioria was also reported from the Miocene Cucaracha Formation in the area of the Panama Canal. The second one belongs to the Malvaceae, however, we cannot place it in any known fossil or extant genus. We propose a new fossil genus, Veraguasoxylon, based on the occurrence of slight tangential arrangement of vessels, paratracheal axial vasicentric parenchyma, apotracheal axial diffuse parenchyma, rays that are 4–10 cells wide, and "Pterospermum" type tile cells. These two new reports contribute to the diversity of plants known from Panama prior to the closure of the Central American Seaway. They also provide further evidence that Azuero hosted a diverse rainforest during the Oligocene–Miocene.