A Maastrichtian terrestrial palaeoenvironment close to the K/Pg boundary in the Golfo San Jorge basin, Patagonia, Argentina

Seed traits linked to differential survival of plants during the Cretaceous/Paleogene impact winter

“…The combination of these traits (short-duration seed viability coupled with rapid maturity in three to five years) suggests that, in the low-resolution stratigraphic record, recolonization of landscapes by nypoid palms should appear instantaneous in the palynological record. This seems to be the case, as the base of the Spinizonocolpites baculatus Zone marks the K/Pg boundary throughout the Southern Hemisphere (Vajda and Bercovici, 2012;Vallati et al, 2020).…”

“…A potential problem with this approach is that species concepts may overlap (e.g., coeval pollen may have been produced by one or more surviving species that are recognized as foliage; Berry, 2019a; Berry, in press); however, due to the differences in taphonomic pathways exhibited among these various types of fossils, this "overlap" in species concepts is probably minimal, particularly as wind-blown palynomorphs are generally interpreted as being representative of species in the broader catchment area of a regional depositional setting (facies-independent fossils), whereas megafossils are generally regarded to be representative of species in a local depositional setting (facies-dependent fossils) (Berry, in press). In other cases, such as in the case of nypoid palms, for example, the geographic distribution of known fossil fruits and pollen are disparate (El-Soughier et al, 2019;Vallati et al, 2020), so this effect probably is negligible. The only fossils included in this study for which there might be significant overlap in species concepts among various types of organs include fossils of Sabalites pollen, fruit and foliage (Manchester et al, 2010).…”

“…Thus, nypoid palms are prone to produce recalcitrant seeds because of their presence in tropical, equable climates with high precipitation/humidity, whereas coryphoid palms are prone to produce orthodox seeds because of their presence in cooler, drier climates (Hong et al, 1997;Wyse and Dickie, 2017). Nypa fruits are known from K/Pg boundary strata in equatorial Africa (El-Soughier et al, 2019), although a diverse pollen assemblage produced by nypoid palms is known throughout the Southern Hemisphere during this time (Raymer, 2010;Vajda and Bercovici, 2012;Vallati et al, 2020).…”

Contribución a La Diversidad Del Registro Fósil De Tortugas (Testudinata) De La Provincia De Chubut (Argentina) Y Su Significado en La Comprensión De La Evolución De Las Tortugas en El Sur De Sudamérica

“…Cretaceous to earliest Paleogene units from the Golfo San Jorge Basin (Lago Colhué Huapí and Salamanca formations) and Somuncurá-Cañadón Asfalto Basin (La Colonia and Lefipán formations). The Lago Colhué Huapí Formation is composed of high sinuosity fluvial systems, deposited under warm and humid climate (Casal et al, 2015(Casal et al, , 2016Vallati et al, 2020). Turtles proceed from the upper part of the unit (Casal, pers.…”

“…comm. ), which in the uppermost levels interfingers with the lowermost strata of the marine Salamanca Formation, giving place to plains with fresh-water ponds and coastal swamps (Casal et al, 2015(Casal et al, , 2016Vallati et al, 2020). Taxa from the Salamanca Formation come from outcrops of the Banco Negro Inferior (Feruglio, 1949) cropping out on the southern coastal area of Chubut Province (Fig.…”