GNAEDINGER silvia cristina
congresos y reuniones científicas
ICHNOTAXONOMICAL CONSIDERATIONS ON THE ENDOPHYTIC OVIPOSITIONS ON LEAVES FROM CARBONIFEROUS TO THE NEOGENE
GNAEDINGER SILVIA; ADAMI RODRIGUEZ, K.,; GALLEGO, O. F.
Congreso; XXIII Congresso Brasileiro de Paleontologia.; 2013
In this contribution, in accordance with the criteria used by many authors, seven new ichnospecies of odonatan endophitic ovipositions are establish and the synonymy of species from reviewed literature (including only the best described and illustrated materials) is proposed. The new ichnospecies are defined based upon their main diagnostic characters: shape and size of the scars and their arrangement on the leaf lamina. In addition, it performs a review of the egg scar records from the Carboniferous to the Neogene for both Laurasia and Gondwana, summarizing their main diagnostic features and their situation within the ichnotaxonomical scheme proposed here, and their known stratigraphic and paleogeographical distributions. Also, it is plotted the distribution of the ichnospecies on a global scale, over the course of the geological history. Through the analysis of the arrangement of egg scars, the stratigraphical and paleogeographical distributions is different across the geological time scale, and show that the organization of these scars on the leaf lamina changes in accordance with the type of venation, and agree with the major floristic turnovers. During the Permian, egg scars are arranged irregularly on the laminar margin or adjacent to it and dispersed on the leaf lamina without a definite pattern. During the Triassic to the Early Cretaceous, arrangements are seen in longitudinal rows or groups always related to the lateral veins. However, from the Late Cretaceous with the evolution of angiosperms, arrangements develop in relation to the reticulate venation in these plants, consisting of primary and secondary veins and the "Lestiden" and "Coenagrioniden" type's characteristic of recent groups are observed.