FIGURE 2. Fossiliferous outcrops of laminated dolomitic limestones in the lower section of the Sierra Madre Formation, near Ocozocoautla de Espinosa, Chiapas, southern Mexico. 1 and 2, El Espinal Quarry, a general view and strata details respectively. 3 and 4, El Chango quarry, a general view and strata details.