Abstract

VELASCO-DE LEON, María Patricia  and  ORTIZ-MARTINEZ, Erika Lourdes. New Quercus (Fagaceae) species from the Pliocene of Santa María Amajac, Hidalgo, Mexico. Rev. mex. cienc. geol [online]. 2010, vol.27, n.2, pp. 264-277. ISSN 1026-8774.

Using foliar architecture seven new fossil species of the Fagaceae Family are described for Mexico: Quercus amajensis, Q. cevalli, Q. curvensis, Q. grandensis, Q. hidalgensis, Q. ovatus and Q. rugosus. Fossil leaf impressions were collected in the areas of Sanctorum and Los Baños, in the Atotonilco El Grande Formation in Hidalgo. The phenetic analysis performed allow us to conclude which characters are important in defining the new species: ramification of the tertiary veins, fifth order venation, shape and size of the areole, the presence of inter-secondary veins and secondary veins ramification within the tooth. These results support the importance of the Trans-Mexican Volcanic Belt as a speciation area.

Keywords : foliar architecture; taxonomy; Quercus; oak; Pliocene; Hidalgo; Mexico.