New glossopterid polysperms from the Permian La Golondrina Formation (Santa Cruz Province, Argentina): potential affinities and biostratigraphic implications

Abstract

-Impression fossils of ovuliferous fructifi cations from the Permian La Golondrina Formation in Santa Cruz, Argentina, are described, their affi nities compared, and fi nally, assigned to the Arberiaceae (Glossopteridales). Based on morphological differences from the genera in Arberiaceae, a new taxon is established for some specimens, whereas others are allocated to Arberia madagascariensis (Appert) Anderson & Anderson. This is the fi rst record of Arberiaceae from the La Golondrina Basin. The biostratigraphic implications of the occurrence of this family in this unit are discussed, and suggest that more evidence other than that provided by the megafl oral elements is needed to resolve the age of the constituent members of the La Golondrina Formation.

Patterns of insect-mediated damage in a Permian Glossopteris flora from Patagonia (Argentina)

“…It is, however, the Laguna Polina Member from where most of the interactions are registered (Supplementary Information 1). This may be a result of both, the extensive spread and finer lithology of the middle member fossil outcrops, which allows better and more detailed preservation of plants, in contrast to the coarser lithology and reduced number of fossil outcrops from the Laguna Lillo and Dos Hermanos members (see Cariglino, 2011Cariglino, , 2015Fig. 2).…”

“…Based on the paleofloristic assemblage, the La Golondrina Formation is considered to range in age from the late Cisuralian to the Lopingian (Archangelsky and Cúneo, 1984;Archangelsky, 2006;Archangelsky et al, 1996). In an attempt to circumscribe the age of the formation, Cariglino (2013Cariglino ( , 2015 used glossopterid fructifications as fossil indices for Permian biostratigraphic correlations. Given every glossopterid fructification was recovered from the Laguna Polina Member, a potential Kungurian-Wuchiapingian age is inferred for the middle member, suggesting at least an Artinskian age for the Laguna Lillo Member, and a Changhsingian age for the Dos Hermanos Member (Archangelsky, 1992;Cariglino, 2013Cariglino, , 2015.…”

“…In an attempt to circumscribe the age of the formation, Cariglino (2013Cariglino ( , 2015 used glossopterid fructifications as fossil indices for Permian biostratigraphic correlations. Given every glossopterid fructification was recovered from the Laguna Polina Member, a potential Kungurian-Wuchiapingian age is inferred for the middle member, suggesting at least an Artinskian age for the Laguna Lillo Member, and a Changhsingian age for the Dos Hermanos Member (Archangelsky, 1992;Cariglino, 2013Cariglino, , 2015. Unfortunately, the finding of other evidences (i.e., paleopalynology, ash or tuff levels) applicable to more reliable dating methodologies in the La Golondrina Formation has turned so far, unsuccessful.…”