FIGURE 1. Map of the location of the study areas. A) Map of the Mexican Republic showing the location of the localities within the state of Puebla. B) Geological map of the Matzitzi Formation. C) Strata of the “Carretera” locality, the arrow indicates the collecting area. D) Strata of the “Coatepec” locality, the arrow indicates the collection area.
FIGURE 2. Stratigraphic sections of the collecting outcrops. A) Sequence of rocks that outcrop on kilometer #89 of the Tehuacán-Oaxaca highway, the two collection zones can be observed. B) Sequence of rocks that outcrop from the river “Paso Hondo” to the outskirts of the town of Coatepec, Puebla; the different collecting layers can be observed.
FIGURE 3. Specimens of cf. Bjuvia sp. A) Largest specimen, CFZ-MTZ540. B) Specimen CFZ-MTZ583, in which a reduction in width toward the edges of the lamina can be observed. C) Close-up of specimen CFZ-MTZ540, in which the type of attachment of the lamina can be observed. D) Parallel venation observed in specimen CFZ-MTZ540. E) Adaxial cuticle extracted from specimen CFZ-MTZ583, with undulating epidermal walls. F) Abaxial cuticle extracted from specimen CFZ-MTZ540, in which straight epidermal cells can be observed. G and J) Stomata in the abaxial part of the cuticle of specimen CFZ-MTZ540, black arrows indicate papillae over stomatal opening and white arrows indicate subsidiary cells. H) Stomatal arrangement observed in the abaxial cuticle. I) Close-up of the adaxial cuticle where a simple trichome is observed, arrow indicates simple trichome. Abbreviations: m, leaf margin; r, rachis. Scale. A 5 cm, B and C 1 cm, D 0.5 cm, E, F and H 100µ, G 10 µ, I-J 50µ.
FIGURE 4. Specimens of leaves of Cycadophytes. A) Nilssonia sp. Specimen CFZ-MTZ266, the arrow indicates an area in which it is observed how the leaf covers the rachis. B) Parallel and dichotomous venation of Nilssonia sp. C) Parallel venation of Taeniopteris lentriculiformis, specimen CFZ-MTZ330. D) Specimen of Taeniopteris lentriculiformis. E) Taeniopteris crassinervis, specimen CFZMtz-713. F) Parallel and dichotomous venation of Taeniopteris crassinervis. Symbols: m, leaf margin; r, rachis; the arrows indicate the areas with dichotomous venation. Scale. A, D-F 1 cm, B and C 0.5 cm.