Sampling biases and Paleozoic sporomorphs diversity dynamics in Western Gondwana strata.

BERI, Á,; DI PASQUO, M.M.; MARTÍNEZ-BLANCO, X.; SOUZA, P.A; LUCIANO VARELA

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2019 vol. 98 p. 1 - 9

0895-9811

Beri, A., Blanco, X., Varela, L., di Pasquo, M., Souza, P.A., 2019. Sampling biases and Paleozoic sporomorphs diversity dynamics in Western Gondwana strata. Journal of South American Earth Sciences. First published version available online: 10-DEC-2019. DOI information: 10.1016/j.jsames.2019.102457A dataset consisting of presence-absence data of 137 pollen and spore genera was elaborated with published sourcesfrom Pennsylvanian and Permian Atlantic (Paraná, Parnaíba, Amazonas, and Claromecó) and Pacific (Paganzo,Tarija, and Madre de Dios) basins of South America. The richness and origination, extinction, and sampling rates ofsporomorphs were analyzed in order to address the effect of sampling biases over diversity estimations. Richness andsampling were estimated using the recently developed True Richness estimated using a Poisson Sampling (TRiPS)model. Origination, extinction, and sampling rates were estimated with Inverse Survivorship Models. The TRiPSanalysis showed changes in richness during the studied interval. The highest richness was observed for theCisuralian, and the lowest richness was recovered for the Pennsylvanian and Guadalupian. The best supportedInverse Survivorship Model revealed that the highest origination values occurred between the Gzhelian and Asselian,whereas the highest observed extinction rate occurred between the Kungurian and the Roadian. In particular, pollengrains showed higher net diversification than spores, while spores showed higher turnover than pollen grains. Also, analternation in richness dominance was observed at the beginning of the Permian, with pollen grains showing higherrichness after the Artinskian. Changes in total sporomorphs diversity, as well as differences between spores andpollen grains, may be related to changing climatic conditions in Western Gondwana during the late Paleozoic (fromicehouse to greenhouse conditions) that could impact differently over plant communities. Although the fossilpalynomorph record has been widely used as a biostratigraphic tool, our results highlight its importance andusefulness for the study of plant communities and their evolution in the past.