Vaquerosella perrillatae sp. nov.: A Miocene species of Echinarachniidae (Echinodermata: Clypeasteroida) from Baja California Sur, Mexico

Abstract

The North American Pacific Coast represents an area with a rich fossil record of Neogene scutelliforms. Here, a new species of echinarachnid sand dollar is described and named as Vaquerosella perrillatae sp. nov., based on 21 well-preserved specimens from the Miocene marine deposits of the San Ignacio Formation, Baja California Sur, western Mexico. The skeleton of this species is characterized by the presence of deep postero-lateral notches and a straight posterior margin. This, the first finding of Vaquerosella in Mexico, represents an important contribution to the knowledge of taxonomical and morphological diversity of this extinct genus and confirms that during the Miocene this had a wider geographical distribution towards the southern region of the Pacific coasts of North America.