Two new species of Ginkgoales from the Middle Jurassic of Mexico

Abstract

This paper reports two new species of Ginkgoales collected from the Cañada Alejandro and Río Ñumi (Zorrillo and Zorrillo–Taberna Undifferentiated Formations, Middle Jurassic). Thirty-one fossils were selected and compared with 14 species from different localities. A numerical taxonomy analysis was performed through a data matrix formed by 15 characters. Results indicate an important speciation process of the Ginkgoales during the Jurassic in the southeast of Mexico. New evidence suggests the existence of eight species from the Ginkgoidium Yokoyama, 1889 and Sphenobaiera (Florin) Harris and Millington, 1974 genera and two new species Ginkgoidiumnundichii Velasco-de León, Lozano-Carmona, Flores, Martínez and Silva and Sphenobaieramixteca Velasco-de León, Lozano-Carmona, Flores, Martínez and Silva

Keywords::

• gymnosperms
• Middle Jurassic
• Ginkgoidium
• Sphenobaiera
• North America

Additional information

Funding

This paper was financially supported through projects Consejo Nacional de Ciencia y Tecnología [grant number 1030773] and the Program de la Dirección General Asuntos del Personal Académico ‘Apoyos a Proyectos de Investigación Tecnológica’ [grant number IN106010-3].