Fossil woods from early Miocene sediments of the El Cien formation, Baja California Sur, Mexico

Abstract

Five fossil woods are described from the Miocene El Cien Formation located in Baja California Sur, Mexico. Their anatomical characters suggest affinity to the Burseraceae, Euphorbiaceae, Leguminosae and Moraceae. The fossil species described here, together with previous records, demonstrate a high familial and generic floristic similarity with the extant vegetation of western Mexico (e.g. Jalisco). This floristic link suggests a landscape dominated by a tropical deciduous or semi-deciduous forest. However, the presence of additional taxa whose living relatives thrive in relatively moist conditions today suggests a relatively humid environment. The floristic similarity between the floras growing in this region today and those existing during the Miocene can be explained by the palaeogeographic link between these two landmasses (Baja California Sur and Western Mexico) that existed until approximately 5 mybp.