Xylological diversity of the Miocene of the locality “Arroyo Maderas”, Marqués de Comillas, Chiapas

Abstract

Two Miocene woods collected in “Arroyo Maderas” locality, Marques de Comillas municipality, Chiapas, collected by members of Paleobotany Laboratory of the Instituto de Geología, UNAM and the Eliseo Palacios Aguilera Paleontological Museum of Tuxtla Gutierrez, Chiapas, are described. Their wood structure have anatomical features that make them different from each other; however, they show affinity to the Humiriaceae and Lauraceae. In the first morphotype, the presence of simple perforated plate, spiral thickenings on vessel element walls element, presence or absence of chambered bers, oil cells between in bers, vessel-ray pitting of different sizes, body rays with procumbent cells in their body and upright or square cells in their tails, and idioblasts with cubic crystals, scanty and diffuse axial parenchyma strongly suggest in Lauraceae. In contrast, the presence of scalariform perforation plate, vasicentric tracheids, intervessel and vessel-ray pits similar in shape and size to intervessel pits, axial parenchyma scanty and vasicentric, rays composed of mixed procumbent, upright and square cells, support a close similarity with Humiriaceae. If these two new reports are added to the Leguminosae described earlier from this locality, the plant community that fossilized in Marques de Comillas, reveals a diverse paleoflora, whose closest leaving representatives are common in the humid tropic.