New records of Bjuvia and Nilssonia from the Permian of Mexico

Abstract

Two new genera have been identified in the Permian of Mexico: cf Bjuvia and Nils-sonia. Along with previously-known Taeniopteris , these confirm the presence of Cyca-dophytes in the upper Paleozoic of Mexico. This substantially increases the geographical and temporal distribution of this group and provides information on the type of environment in which these plants developed. The new reports come from two localities of the Matzitzi Formation, in the state of Puebla, Mexico, called Carretera (Ca) and Coatepec (Co). In the first locality, we identified material characterized by the presence of a simple leaf of large size with veins perpendicular to the rachis and always parallel, as well as a stomatal apparatus with papillae. The fragmentary nature of the material from Puebla allows only an affinity to Bjuvia of the order Cycadales. Other specimens are assigned to Taeniopteris and Nilssonia . The Nilssonia reported from Carretera, has a segmented lamina attached to the rachis on the upper side. Tae-niopteris is characterized by an entire lamina, generally narrow, with veins originating perpendicularly to the rachis that dichotomizes one or several times. The species T. lentriculiformis and T. crassinervis are reported for the first time from Coatepec. Together with these genera