New genus for megaphyllous leaves from the Upper Paleozoic of Mexico Velascoa pueblensis gen. nov

The paleoflora of the Matzitzi Formation has been studied since the beginning of the last century. Recent surveys have allowed the collection of abundant unregistered material, within which there is a notable group of leaves with a morphology similar to Ginkgophyta. The morphological analysis of more than 100 specimens resulted in the identification of large laminae with a long petiole, fan-shaped leaves with dichotomous venation and a characteristic constant segmentation that occurs up to three times and ends at the apex with 12 segments. It exhibits epidermal cells with sinuous to crenulated walls on the abaxial side, where anomocytic stomata and trichome bases can be observed. Given the absence of reproductive structures and the age of the material, its affinity to the order Ginkgoales is not possible; the comparisons were thus made with genera of the artificial group Ginkgophyta from different localities of the Upper Paleozoic. The results show significant morphological differences that support the proposal of a new genus and species, denominated Velascoa pueblensis. We also identified 10 orders and 27 genera that update the floristic lists created over 50 years ago. This information is important since it will allow to resolve future taxonomic, distributional, and/or environmental aspects that allowed the establishment of the taxa mentioned above.