TABLE 1. Partial list of the Valsequillo fauna, by M. Pichardo, 1966. The Tetela fauna includes collections from the Valsequillo Gravels peripheral to the Valsequillo Reservoir. The Barranca fauna includes collections from detached alluvial outcrops north of the reservoir, thought at the time to be graded to the Valsequillo Gravels. Equus sp. B from the Barranca fauna was found at Bca. de Santa Tlanepantla with shells dated 20,780 ± 800 BP (W-1897). Molars of Equus sp. C from the Barranca fauna was found as "float" at Bcas. Caulapan and Xochiac (Zacachimalpa). Equus sp. D from the Tetela fauna is known only from La Mata on Rio Alseseca near Totimehuacan. Camelops from the Barranca fauna was found at Bca. de Caulapan about 1.6 km upstream from locality R14 and tentatively assigned to beds higher than the basal part of R14.