Frenguelli described a fossil leaf assemblage of 36 taxonomic units (nine gymnosperms and 27 angiosperms) collected from ten localities in southwestern Patagonia. Frenguelli's article has two limitations according to present-day standards: 1) most of the material was neither described nor illustrated; 2) the fossiliferous localities were not associated to any formal stratigraphic unit. We revised the fossiliferous outcrops and the descriptions and systematics of the angiosperm taxa of this collection. We explored the original fossiliferous localities and we included them into three formal stratigraphic units: Río Turbio, Río Guillermo, and Río Leona formations. We recognized 27 taxa: seven were assigned to known fossil-species, we kept 18 in open nomenclature and we synonymized the other two to another genus. In addition, we reported paleofloristic information of each unit: in the Río Turbio Formation the first record of the Salicaceae (Thouinia philippii?); in the Río Guillermo Formation the first record of the Grossulariaceae, Lauraceae and Salicaceae; and in the Río Leona Formation we described Nothofagus variabilis and Escalloniiyphyllum sp. for the first time.

This paper studies the Late Holocene benthic foraminifera from a continuous core extracted in the Doñana National Park (SW Spain). In this core, the foraminiferal assemblages confirm the Late Holocene lagoon (historically so-called Lacus Ligustinus) during the Roman period, about 2000 years ago. The more open, deepest areas of this lagoon were dominated by Ammonia tepida and Elphidium spp., while Haynesina germanica was the most representative species of the shallow, more restricted zones. The vertical variations of these assemblages, together with associated sedimentological and macrofaunal changes, allow recognizing three high-energy events (HEE) between 500 BCE and 500 CE, which also left an extensive sedimentary record in nearby coastal areas: two tsunamis (HEE-1 and HEE-3) and a storminess period (HEE-2).

The genus Pratulum is one of the most abundant genera of Cardiidae in formations of Cenozoic age in New Zealand, Australia, and Antarctica. Currently, three species are known to inhabit the warm seas of Australia and New Zealand. Here, two new species are described, Pratulum kurrawchipellu sp. nov. and Pratulum terpoorteni sp. nov., extending its biogeographic distribution to South America, specifically to lower Miocene localities of central and southern Chile. Also, this finding contributes additional evidence that reaffirms the faunistic relationship between South America, Australia, New Zealand, and Antarctica during the Cenozoic, adding another genus to the list of mollusks that shares its distribution among these regions.

We revise the mammal fossils from the Fray Bentos Formation previously assigned to Notoungulata, as well as some new remains recovered from levels cropping out in Corrientes Province (Argentina). In some cases, previous determinations have been completed to the species level, but others have been substantially modified, identifying different families. At present, identified taxa are: “Prohegetotherium” schiaffinoi (Hegetotheriidae), an undetermined interatheriid that is hypothesized as representing the upper teeth of Eopachyrucos ranchoverdensis, and Argyrohyrax proavus (Interatheriidae), cf. Archaeohyrax suniensis (Archaeohyracidae), cf. Mendozahippus fierensis (“Notohippidae”), a Leontiniidae indet., and some undetermined Notoungulata. The presence of Leontiniidae is based on the specimen CTES-PZ 7871, but those previously assigned to this family are herein discarded as such and reinterpreted (notohippid and undetermined taxon). The Mesotheriidae are discarded among the revised materials, but they are present in the Fray Bentos Formation in Corrientes Province with Trachytherus spegazzinianus (= Ameghinotherium curuzucuatiense). The revised sample presents affinities with the fauna from the type locality of the Fray Bentos Formation, in Uruguay, and the Deseadan assemblages from Quebrada Fiera (Mendoza Province, Argentina), Patagonia (Argentina), and Salla (Bolivia). These similarities are important from a paleobiogeographic point of view, especially by the recognition of cf. M. fierensis, a species only known from Mendoza up to now. Only the finding of new material from Fray Bentos Formation in Corrientes Province will allow us to corroborate these tentative determinations and a possible eastward extension of up-to-now exclusive taxa from Quebrada Fiera.

The Paleozoic evolution of Patagonia was the focus of controversies between its allochthonous or autochthonous origin. The arrival of plate tectonics supported new allochthonous alternatives and from an initial fixist resistance, different mobilistic hypotheses have made their way. There is currently some consensus about its allochthony, but there is no agreement on collision times or in the configuration of the continental blocks involved. Based on the present data an alternative is developed that fits better with existing information. The northeast-vergent deformation in Ventania System, the Hespérides Basin, its wide longitudinal and transverse distribution, show that collision occurred in the northern sector of Northern Patagonian Massif, and extended through the southern African Gondwanides. Their similar metamorphic and tectonic patterns identified a previous southward subduction with a Permian climax, characteristic of a continent-continent collision. The associated magmatic arc has been partially obliterated by slab-breakoff and delamination in the Late Permian–Triassic. The western magmatic belt along the Pacific margin is older, spanning from Devonian to mid-Carboniferous. The Chaitenia island arc collision in Upper Devonian produced an episode of exhumation and uplift. This western belt extends into Tierra del Fuego island and its contour allows tentatively to recognize a Southern Patagonian terrane. It is speculated that this block may have included the Antarctic Peninsula, although more data is needed to characterize its composition and areal development. However, it is concluded that the dimensions of this southern terrane cannot justify the broad regional deformation of the Gondwanides.

The basement of northeastern Patagonia is characterized by Early Paleozoic igneous and metamorphic rocks that do not crop out in the central, western and Andean sectors of the North Patagonian Massif. A review of U-Pb geochronology, geochemistry, and the Nd, Sr, Hf and O isotope signature of the early Cambrian and early Ordovician magmatic rocks supports the hypothesis that the continental crust of northeastern Patagonia was essentially continuous with that of the Eastern Sierras Pampeanas in early Cambrian times. Mesoproterozoic lower crust is also inferred for this sector. New zircon Hf and O analyses of early Cambrian (Pampean) granites in the Sierras Pampeanas are indistinguishable from those of Cambrian granites in NE Patagonia, indicating an important crustal component in the source. The detrital zircon age patterns of the inferred basement are also similar in the two regions, strongly suggesting a southern Kalahari provenance. A modified hypothesis to explain the continuity of NE Patagonia with the Pampean belt of the Sierras Pampeanas during early Cambrian times, as well as their SW Gondwana geological affinity, is to consider this entire belt as an outboard sector of the mid-Cambrian rifting observed along the South America–South Africa–Weddell Sea margin. The detached sector would then have become juxtaposed against the Río de la Plata craton across the right-lateral Córdoba fault in late Cambrian times.

Paleoclimate traits are highly varied at the diverse paleoflora of the Río Genoa Formation in Patagonia. They are thoroughly analyzed in order to define macroclimate parameters that ruled the terrestrial vegetational growth during the early Permian. Plant-climate relationships have been historically used for understanding the distribution of present/past vegetation since they represent a continuous feedback along the terrestrial environments on Earth. Most of the indicators found in Patagonia clearly suggest warm and humid conditions during the entire deposition of the studied unit. Such conditions, related to subtropical climates, cannot be correlated with paleoclimate approaches originated from other proxies. This is due to several imprecisions that affect the interpretation of the paleogeographic position of Patagonia. Different hypotheses are erected in order to explain the paleofloristic and paleoclimatic anomaly present in southern South America, which should encourage new efforts to better understanding the geological dynamics of southwestern Gondwana.