Evidences of Teratology and Mutagenensis in Palynological Assemblages from the Middle Triassic Puesto Viejo Group, San Rafael Depocenter, Argentina. Implications of Volcanism and Regional Environmental Stress

Middle Triassic Continental Palynological Assemblages of San Rafael Depocenter, Central-Western Argentina

“…The varied and diverse microfloristic assemblages of this unit (Fig. 7) include 278 species of palynomorphs (see Appendix: 73 spores, 185 pollen grains, 11 algae, 5 fungi, and 3 incertae sedis; Zavattieri et al, 2020;Gutiérrez & Zavattieri, 2021, this paper) (Cariglino et al, 2018;Gnaedinger et al, 2020;Spalletti et al, 2003;Zavattieri & Gutiérrez, 2022, 2023.…”

“…The terrestrial and aquatic vegetation grew associated with shallow water bodies in floodplain environments developed under warm temperate, strongly seasonal climatic conditions when profuse volcanic activity introduced large volumes of ash and greenhouse gases into the atmosphere. The volcanic events developed during deposition of the QdlF Fm promoted changes in the environmental conditions that influenced the development of the peculiar composition of the vegetation and algae community in the water bodies, creating stressful conditions and the development of the plant communities within the ecosystem (Cariglino et al ., 2018; Gnaedinger et al , 2020; Spalletti et al ., 2003; Zavattieri & Gutiérrez, 2022, 2023).…”

“…The vegetation reflected by the palynoflora of both sections of the QdlF Fm is characterized by variable compositions of spores and pollen grains (SOI 4), it is mainly dominated by spores of lycophytes and sphenophytes, together with less common true ferns that inhabited humid terrestrial environments surrounding the deposit area (para- autochthonous elements). A plant community of low diversity is dominated by stress-tolerant plants, which developed in an ecosystem that is repeatedly affected by volcanism (Zavattieri & Gutiérrez, 2022, 2023). Pollen grains derived from gymnosperms s.l.…”