A new fossil wood of Calophyllaceae from the Tepetate Formation (Eocene, Bartonian), Baja California Sur, Mexico

Abstract

We describe a new fossil species belonging to the Calophyllaceae, collected from southern Baja California Sur, Mexico. This new wood is characterized by the presence of distinct growth ring boundaries, mostly solitary vessels, alternate intervessel pitting, vessel-ray parenchyma pits with reduced borders, vasicentric tracheids; non septate and septate fibers combined; axial parenchyma diffuse, diffuse-in-aggregates, scanty paratracheal and vasicentric; heterocellular rays, and large radial canals, usually one per ray, located in the center of the rays. The characteristics present in the fossil wood, although diagnostic for the Calophyllaceae, do not resemble any fossil or extant species within the family; therefore, we assign it to a new fossil species named Mammea martinezii. This is the first formal record of a fossil wood of Calophyllaceae in Mexico. The occurrence of this family in the middle Eocene (Bartonian) of southern Baja California Sur contributes to the understanding of the historical distribution of the family and its geological history and importance in forests of northern Mexico.