Search

This contribution presents a comprehensive study of the unique and rich terrestrial Middle Triassic palynoflora recovered from the Quebrada de los Fósiles Formation, lower unit of the Puesto Viejo Group, San Rafael Depocenter, Mendoza Province, Argentina. The palynoflora was recorded at two sections of the unit (Quebrada de los Fósiles creek and Río Seco de la Quebrada creek), yielding diverse and well-preserved spores, pollen, freshwater algae, and fungal associations. Herein, 259 spore-pollen species are described and/or illustrated, from which eight are new: Baculatisporites magnus sp. nov., Carnisporites microspinous sp. nov., Leschikisporis variabilis sp. nov., Neoraistrickia stricta sp. nov., Limatulasporites rugulatus sp. nov., Aratrisporites circularis sp. nov., Protohaploxypinus bonapartei sp. nov. and P. diazii sp. nov. The following new combinations are proposed: Brevitriletes decorus comb. nov., B. pamelae comb. nov., B. sandrae comb. nov., Cuneatisporites cacheutensis comb. nov., C. salujhai comb. nov., and Pityosporites thoracatus comb. nov. A new emendation for Alisporites cymbatus is instituted, and A. libyaensis nom. nov. is a new name to replace A. plicatus. These microfloras present varied parental vegetation, containing high proportions of spores from Pleuromeiales, Equisetales, Marattiales, and Corystospermales pollen. The grains of Araucariaceae, Cupressaceae, Voltziales, Cordaitales, Gnetales, and Ginkgoales/Cycadales are recorded in smaller proportions. Zygospores of chlorophytic algae and fungi are also recorded in these assemblages. The microflora of the Quebrada de los Fósiles Formation is distinctive, quantitatively and qualitatively, from the rest of the Triassic microfloras, exhibiting the highest similarities in its composition with the associations of the La Veteada (Early Triassic, Olenekian) and Cerro de Las Cabras (Late Anisian-Early Ladinian) formations. [ABSTRACT FROM AUTHOR]

Sterile and fertile fronds of dipteridacean ferns from the Paso Flores Formation (late Norian-Rhaetian) at Cañadón de Pancho area, south of the Neuquén Province, Patagonia (Neuquén Basin), Argentina, are described. The Paso Flores Formation specimens comprise an interesting mixture of features showing a unique combination that does not fit in the diagnosis of any of the known fossil genera of Dipteridaceae. Characters such as the number and shape of primary segments in each rachial arm, the coalescence of the primary segments at the base of the frond, the distribution of sori and the number of sporangia per sori allow to differentiate the Paso Flores Formation specimens from the other genera of the family. The new genus and species, Patagoniapteris artabeae is proposed. The specimens share some frond morphological features with the fossil genera Clathropteris, Digitopteris, Thaumatopteris, Sewardalea and with some species of the Dictyophyllum, as well as the characteristic of the sori with the living species Dipteris lobbiana. The Paso Flores Formation environments developed on the western margin of Gondwana under seasonal temperate-warm and humid to sub-humid climates with a marine influence from the west. The Cañadón de Pancho assemblages are late Norian-Rhaetian in age, being the youngest fossil flora recorded from Argentinian Triassic basins to date. [ABSTRACT FROM AUTHOR]

Sterile and fertile fronds of dipteridacean ferns from the Paso Flores Formation (late Norian-Rhaetian) at Cañadón de Pancho area, south of the Neuquén Province, Patagonia (Neuquén Basin), Argentina, are described. The Paso Flores Formation specimens comprise an interesting mixture of features showing a unique combination that does not fit in the diagnosis of any of the known fossil genera of Dipteridaceae. Characters such as the number and shape of primary segments in each rachial arm, the coalescence of the primary segments at the base of the frond, the distribution of sori and the number of sporangia per sori allow to differentiate the Paso Flores Formation specimens from the other genera of the family. The new genus and species, Patagoniapteris artabeae is proposed. The specimens share some frond morphological features with the fossil genera Clathropteris, Digitopteris, Thaumatopteris, Sewardalea and with some species of the Dictyophyllum, as well as the characteristic of the sori with the living species Dipteris lobbiana. The Paso Flores Formation environments developed on the western margin of Gondwana under seasonal temperate-warm and humid to sub-humid climates with a marine influence from the west. The Cañadón de Pancho assemblages are late Norian-Rhaetian in age, being the youngest fossil flora recorded from Argentinian Triassic basins to date. [ABSTRACT FROM AUTHOR]