Paleoclimate and paleoecology of the Upper Oligocene Tehuacán Formation, Puebla State, Mexico, as determined from wood anatomical characters

Abstract

Climatic conditions that prevailed during the deposition time of the Tehuacán Formation, Mexico (upper Oligocene) are proposed based on a previous model using wood anatomical characters. Different paleoclimatic variables were calculated, and the anatomical characteristics of the Tehuacán Formation paleoflora were compared with the characteristics of other extant and fossil plant communities to infer water conductive capacities of the Tehuacán Fm. plants. The paleoclimatic inference suggests that the environmental conditions under which the fossilized plants of the Tehuacán Fm. grew were seasonally warm and humid. Statistical analysis and the presence of growth rings in some woods suggest that the paleoflora of the Tehuacán Fm. were similar to extant tropical communities such as tropical semi-deciduous forests and the tropical deciduous forests, most probably representing a transitional community: containing plants that were efficient in transporting water like those in the tropical wet forests, but with phenological adaptations typical of drier tropical forests. Marco A. Rubalcava-Knoth. Posgrado en Ciencias Biológicas, Instituto de Geología, UNAM; Ciudad Universitaria, Circuito de la Investigación Científica, Copilco El Alto, Coyoacán; 04510 Mexico D.F., Mexico. paleoplantas@gmail.com Sergio R.S. Cevallos-Ferriz. Departamento de Paleontología, Instituto de Geología, UNAM; Ciudad Universitaria, Circuito de la Investigación Científica, Copilco El Alto, Coyoacán; 04510 Mexico D.F., Mexico. scrscfpb@unam.mx