Taeniopteris crassinervis (Feistmantel) Arber, 1917

Flores-Barragan, Miguel Angel & Leon, María Patricia Velasco-de, 2020, New records of Bjuvia and Nilssonia from the Permian of Mexico, Palaeontologia Electronica (a 28) 24 (3), pp. 1-17 : 11

Taeniopteris crassinervis (Feistmantel) Arber, 1917

Figure 4 E-F

Material. CFZMTZ-713.

Locality. Coatepec.

Description. Entire lamina, with entire margins, 6.8 cm long and 5.3 cm wide at the mid-part. The leaf width appears to be constant. The shape of the base and apex are unknown. Undulations are observed in the lamina, which could be the result of desiccation and/or the fossilization process. The lamina attaches laterally to the rachis. The rachis is slim, retaining its width throughout the whole leaf with a maximum width of 0.3 cm. The veins emanate from the rachis at 90°. This venation divides at the proximal part of the rachis and then becomes parallel along it. It can have a density of up to 14 to 16 veins per centemeter at the mid-part of the leaf. Remarks. After comparing it with 42 different species of the genus ( Table 4 ), the specimen from Puebla was assigned to the species Taeniopteris crassinervis , since it exhibits strong veins with a similar venation density and perpendicular angle at which they are inserted regarding to the rachis. Another diagnostic characteristic of this species is the dichotomy of the veins in the contact area with the rachis ( Figure 4E ). This species has been reported for the Triassic of Argentina ( Artabe, 1985), United States, India, Australia, New Zealand, and Africa (Beherensmeyer and Turner, 2019). This new report would correspond to the most southern record of North America.

Figures

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.