China Built a Satellite Ground Station in Argentina, but Reneged on Agreements After

When China built a military-run space station in Argentina’s Patagonian region it promised to include a visitors’ center to explain the purpose of its powerful 16-story antenna.

The center is now built - behind the 8-foot barbed wire fence that surrounds the entire space station compound. Visits are by appointment only.

Shrouded in secrecy, the compound has stirred unease among local residents, fueled conspiracy theories and sparked concerns in the Trump administration about its true purpose, according to interviews with dozens of residents, current and former Argentine government officials, U.S. officials, satellite and astronomy specialists and legal experts.

The station’s stated aim is peaceful space observation and exploration and, according to Chinese media, it played a key role in China’s landing of a spacecraft on the dark side of the moon in January.

But the remote 200-hectare compound operates with littleoversight by the Argentine authorities, according to hundreds of pages of Argentine government documents obtained by Reuters and reviewed by international law experts.

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Allkaruen koi: a new Patagonian Pterosaur From the Lower Jurassic

Scientists today announced the discovery of a new species of pterosaur from the Patagonia region of South America. The cranial remains were in an excellent state of preservation and belonged to a new species of pterosaur from the Early Jurassic. The researchers have named this new species 'Allkauren koi' from the native Tehuelche word 'all' for 'brain', and 'karuen' for 'ancient'.

Pterosaurs are an extinct group of flying reptiles that lived during most of the Mesozoic Era. This group had an extraordinary adaptation to flight, including pneumatic bones to lighten its weight, and an elongated digit supporting a wing membrane. However, pterosaur neuroanatomy is known from only a few three dimensionally preserved remains and, until now, there was no information on the intermediate forms. This study therefore provides new information on the origin, tempo and mode of evolution in this particular group of flying reptiles.

The fossil of Allkaruen koi was found in northern central Chubut Province, Patagonia Argentina and the remains included a superbly preserved and uncrushed braincase. In order to study the neurocranial anatomy, researchers used computed tomography to observe, in three dimensions, the cranial endocast and the inner ear. Subsequently, a comprehensive phylogenetic analysis of the group was performed, including these cranial data and other anatomical features. "Allkaruen, from the middle lower jurassic limit, shows an intermediate state in the brain evolution of pterosaurs and their adaptations to the aerial environment", said Dr Diego Pol, who is part of the research team. "As a result, this research makes an important contribution to the understanding of the evolution of all of pterosaurs."

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Murusraptor barrosaensis: a new megaraptorid Theropod From Cretaceous Argentina

A new species of megaraptorid dinosaur discovered in Patagonia may help discern the evolutionary origins of the megaraptorid clade, according to a study published July 20, 2016 in the open-access journal PLOS ONE by Rodolfo Coria from the Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina, and Phillip Currie from the University of Alberta, Canada.

The Patagonian region of Argentina has previously proven to be rich in fossils from the Late Cretaceous epoch, including a number of megaraptorids, a clade whose carnivorous diet gave rise to their name meaning 'giant thieves'. These medium-sized theropod dinosaurs, including South American genera Megaraptor, Orkoraptor, and Aerosteon as well as genera from Australia and Japan, have characteristically large claws and air-filled, birdlike bones.

The fossilized partial skeleton of a megaraptorid dinosaur analyzed in this study was discovered in Sierra Barrosa, in northwest Patagonia and represents one of the most complete megaraptorids found, with an unusually intact braincase. With unique skull features, the dinosaur, which they named Murusraptor barrosaensis, is a new species in the megaraptorid clade. This specimen appears to be immature, but the authors suggest that the species is larger and slenderer than Megaraptor and comparable in size with Aerosteon and Orkoraptor. While sharing many features with the other species, Musuraptor has distinctive facial features not previously seen amongst megaraptorids, as well as unusually shaped hip bones.

While phylogenetic analysis could not clearly determine evolutionary relationships, the authors note that these fossils provide new anatomical information which might help to resolve current debates as to whether the megaraptorids are a clade of the allosauroid or the coelurosaurid theropods.

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Gualicho shinyae: a Neovenatorid Carcharodontosaurian Theropod With a Tyrannosaur-like Hand From Cenomanian Cretaceous Argentina

An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina

Authors:

Apesteguía et al

Abstract:

Background

Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodontosaurid theropods. Continued sampling is adding to the known vertebrate diversity of this unit.

Methodology/ Principal Findings

A new, partially articulated mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a unique combination of traits that distinguish it from other known theropods justifying erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a didactyl manus with the third digit reduced to a metacarpal splint reminiscent of tyrannosaurids, but both phylogenetic and multivariate analyses indicate that didactyly is convergent in these groups. Derived characters of the scapula, femur, and fibula supports the new theropod as the sister taxon of the nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian. A number of these features are independently present in ceratosaurs, and Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran synapomorphies distributed throughout the skeleton.

Conclusions/ Significance

Gualicho shinyae gen. et sp. nov. increases the known theropod diversity of the Huincul Formation and also represents the first likely neovenatorid from this unit. It is the most basal tetatanuran to exhibit common patterns of digit III reduction that evolved independently in a number of other tetanuran lineages. A close relationship with Deltadromaeus from the Kem Kem beds of Niger adds to the already considerable biogeographic similarity between the Huincul Formation and coeval rock units in North Africa.

pop sci write up.

Ground Sloths Spread Into North America Multiple Times

The manus of Mylodon darwinii Owen (Tardigrada, Mylodontidae) and its phylogenetic implications

Authors:

Haro et al

Abstract:

The first nearly complete and articulated manus of the ground sloth Mylodon darwinii, from the upper Pleistocene of Argentina, is described. It shares similarities with Mylodonopsis ibseni from Brazil, including a cuneiform with a distinct pisiform facet, an obliquely concave ulnar facet, and a prominent distolateral process, as well as a gracile metacarpal III. It shares a flattened pisiform with Glossotherium robustum. The trapezoid is unique in the obliquely elongate proportions of its dorsal surface. Shapes of the articular facets indicate different functions in digits II and III, with the former having a greater range of motion and the latter greater stability at the joints. Clear arboreal or fossorial adaptations are absent. A phylogenetic analysis recovered M. darwinii as closely related to M. ibseni and agrees with larger phylogenetic analyses of sloths based on craniomandibular evidence. Our data support more than two mylodontine dispersal events to North America.

Ecological Changes During the Glacial & Interglacials of the late Paleozoic ice age of Pennsylvanian Carboniferous Argentina

Compositional turnover and ecological changes related to the waxing and waning of glaciers during the late Paleozoic ice age in ice-proximal regions (Pennsylvanian, western Argentina)

Author:

Balseiro

Abstract:

The late Paleozoic ice age (LPIA) had a profound effect on the biota. Despite much research having been focused on paleotropical regions or global-scale analyses, regional ecological changes have seldom been studied in ice-proximal basins. Here, I study the compositional turnover and diversity structure across the main Carboniferous glacial event recorded in western Argentina and the subsequent nonglacial interval. Brachiopod and bivalve data from western Argentina suggest that the transition from glacial to nonglacial climates caused major compositional changes. Turnover, however, was not uniform across the bathymetric gradient, being higher in deep environments. Because extirpation was concentrated in brachiopods, but immigration was similar in both clades, the taxonomic structure of the region was significantly modified. Although regional hierarchical diversity structure and occupancy distributions remained stable, dissecting the analysis in brachiopods and bivalves underscores that both clades had different responses to climate change. Brachiopods, on the one hand, show stability in the diversity structure and a very slight decrease in occupancies of intermediate genera, while bivalves show an important rise in diversity, both at the environment and regional scale, and an increase in genera with intermediate occupancies. The bathymetric diversity gradient was also modified from hump shaped with maximum diversity in the deep subtidal to a linear gradient with maximum values toward the offshore. However, relative compositional differences within environments remained stable, with maximum values at intermediate depths both in glacial and nonglacial intervals. Moreover, local-scale coexistence between brachiopods and bivalves changed in the nonglacial interval, showing significant segregation, which indicates relevant modifications in community assembly dynamics. Results from western Argentina highlight the magnitude of regional-scale ecological changes during the LPIA in ice-proximal regions, suggesting that the waxing and waning of glaciers was able to cause regional taxonomic turnover and medium-scale ecological changes even during intervals of relative macroevolutionary quiescence.

Pampahippus secundus: a new Toxodont Notoungulate From Eocene Paleogene Argentina

A new Eocene Toxodontia (Mammalia, Notoungulata) from northwestern Argentina

Authors:

Deraco et al

Abstract:

A new species of Toxodontia (Mammalia, Notoungulata), Pampahippus secundus sp. nov., is described based on remains recovered from outcrops of the Lumbrera Formation exposed in Salta Province, northwest Argentina. The material studied consists of mandibular, maxillary, and premaxillary fragments with complete and incomplete teeth representing at least three individuals. It differs from the type species P. arenalesi by its smaller size and the presence of several dental features: I2 smaller than the I1 and I3, paraconule absent on the P3, upper molars wider than long and subquadrangular, with a single crista projecting from the ectoloph, strong mesiolingual cingulum surrounding the protocone on the M1, conspicuous metacone fold on the ectoloph of M1 and M2, and absence of labial cingulids on lower molars. In order to determine the phylogenetic position of P. secundus as well as different Paleogene notoungulates of northwestern Argentina, we performed a cladistic analysis. This analysis supports the paraphyly of Notohippidae proposed by previous authors and validates the monophyly of the genus Pampahippus, which ranks as a relatively basal taxon within Toxodontia. This contribution illustrates the significant and yet poorly known diversity of Paleogene toxodontians from northwestern Argentina and the importance of their study in the reconstruction of the evolutionary history of Notoungulata.

Early Holocene Population Dynamics in Northwest Patagonia

Past population dynamics in Northwest Patagonia: An estimation using molecular and radiocarbon data

Authors:

Ivan Perez et al

Abstract:

Studying demographic changes in past human populations is of great interest due to their role in processes of cultural change as well as the biological evolution of populations. Despite this, a general consensus about the most adequate methodological approach to this end is still lacking. Here, a new approach that combines radiocarbon frequency distributions —uncorrected and corrected by taphonomic bias— and demographic curves independently estimated with modern mitochondrial DNA (mtDNA) is used to estimate population size changes in Northwest Patagonia since the Pleistocene–Holocene transition to recent times. Results based on mtDNA sequences suggest a census size of approximately 3000 individuals (with an estimated female effective size of ca. 750 individuals) by the initial peopling of this region around 10,000 years ago. A strong correspondence between curves based on mtDNA data and those based on archaeological radiocarbon dates (n = 251) was obtained after the effect of taphonomic bias was accounted for. The demographic curves indicate that the population size was relatively stable during the earlier Early Holocene and it increased between 7000 and 5000 years ago, reaching a maximum size around 1000 years ago. Then, the population size declined until present time. We conclude that demographic inferences made on the basis of radiocarbon dates are not necessarily biased but this needs to be evaluated with independent evidence in each specific geographical region.

Archosauriforms From a Flood Plain in Late Triassic Argentina

Archosauriform remains from the Late Triassic of San Luis province, Argentina, Quebrada del Barro Formation, Marayes–El Carrizal Basin

Authors:

Gianechini et al

Abstract:

Here we present archosauriform remains from ‘Abra de los Colorados’, a fossiliferous locality at Sierra de Guayaguas, NW San Luis Province. Two fossiliferous levels were identified in outcrops of the Quebrada del Barro Formation (Norian), which represent the southernmost outcrops of the Marayes–El Carrizal Basin. These levels are composed by massive muddy lithofacies, interpreted as floodplain deposits. The specimens consist of one incomplete maxilla (MIC-V718), one caudal vertebra (MIC-V719), one metatarsal (MIC-V720) and one indeterminate appendicular bone (MIC-V721). The materials can be assigned to Archosauriformes but the fragmentary nature and lack of unambiguous synapomorphies preclude a more precise taxomic assignment. The maxilla is remarkably large and robust and represents the posterior process. It preserved one partially erupted tooth with ziphodont morphology. This bone shows some anatomical traits and size match with ‘rauisuchians’ and theropods. MIC-V719 corresponds to a proximal caudal vertebra. It has a high centrum, a ventral longitudinal furrow, expanded articular processes for the chevrons, a posteriorly displaced diapophysis located below the level of the prezygapophyses, and short prezygapophyses. This vertebra would be from an indeterminate archosauriform. MIC-V720 presents a cylindrical diaphysis, with a well-developed distal trochlea, which present resemblances with metatarsals of theropods, pseudosuchians, and silesaurids, although the size matches better with theropods. MIC-V721 has a slender diaphysis and a convex triangular articular surface, and corresponds to an indeterminate archosauriform. Despite being fragmentary, these materials indicate the presence of a diverse archosauriforms association from Late Triassic beds of San Luis. Thus, they add to the faunal assemblage recently reported from this basin at San Juan Province, which is much rich and diverse than the coeval paleofauna well known from Los Colorados Formation in the Ischigualasto–Villa Union Basin.

Argentina to Procure 14 Kfir Fighters

The joint proposal by Argentina and Israel raises the transfer, refurbishment and modernization of 14 aircraft Kfir (2 seater training and 12 monopostos), some of them equipped with active electronically scanned radar (AESA, by its acronym in English), system data Link for sharing information between units of the fleet and the full fleet maintenance for five years; an operation that materialize would reach about 320 million.

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A Conifer Woodland From Aptian/Albanian Cretaceous Patagonia

Aptian–Albian Cupressaceae (sensu stricto) woods from Cañadón Asfalto Basin, Patagonia Argentina

Authors:

Brea et al

Abstract:

This paper describes the first macrofloristic record from Los Adobes Formation (Chubut Group) in Cañadón Asfalto Basin (Patagonia, Chubut Province, Argentina). The studied fossils were recovered from the Aptian–Albian Bardas Coloradas Member, and consist of silicified woods preserved in fluvial channel deposits. One wood shows homocellular rays with smooth radial and tangential walls, diffuse axial parenchyma, tracheid pitting of the abietinoid type and cross-field pitting cupressoid usually ordered in rows and columns indicating placement within Cupressinoxylon hallei Kräusel. This fossil tree resembles some members of the extant Cupressaceae s.s., as Austrocedrus chilensis (D. Don) Pic. Serm. & Bizzarri, Pilgerodendron uviferum (D. Don) Florin, Fitzroya cupressoide (Molina) I. M. Johnst. and Libocedrus plumosa (D. Don) Druce. Due to poor preservation the other fossil wood specimen was assigned to cf. Cupressinoxylon Göppert 1850 nom. cons. prop. This is the first unequivocal record of C. hallei from the Cretaceous of South America and the oldest reliable record of the Callitroideae, indicating that this subfamily was well established since the mid-Cretaceous in the Southern Hemisphere.

A new Norian/Rhaetian Triassic Vertebrate Assemblage from Argentina

A NEW LATE TRIASSIC VERTEBRATE ASSEMBLAGE FROM NORTHWESTERN ARGENTINA

Authors:

Martínez et al

Abstract:

The Quebrada del Barro Formation (QBF) is part of the continental Marayes-El Carrizal Basin, in NW Argentina. Here we report a diverse faunal assemblage recently discovered at the Quebrada del Barro Formation, along with a preliminary discussion of the taxonomic status and affinities of numerous vertebrate specimens found at two localities of this unit. The new vertebrate association includes remains of at least 12 different new species related to six major vertebrate groups: Cynodontia, Testudinata, Sphenodontia, Pseudosuchia, Pterosauria, and Dinosauromorpha. The most abundant specimens in this faunal assemblage are opisthodontian sphenodonts, tritheledontid cynodonts and basal sauropodomorph dinosaurs, but the assemblage also includes diagnostic remains of lagerpetid dinosauromorphs, theropods, pterosaurs, basal crocodylomorphs, and stem testudinatans. Several of these groups have also been reported for the Los Colorados Formation (LCF), although the two units differ in their taxonomic content at the species level and in the relative abundance of different taxonomic groups. A comparison of these two faunal assemblage suggest the fauna of QBF is younger than that of LCF and we tentatively assess a late Norian–Rhaetian age for the QBF. Some of the specimens reported here are known from well-preserved specimens and contain important new information for understanding the evolution of these groups, which underscores the relevance of the QBF fauna for assessing the dynamics of the major groups of vertebrates that dominated the terrestrial ecosystems during the early Mesozoic in Pangea.

Bitcoin Invading Argentina. Will it Conquer?

Dante Castiglione stalked through the doors of a glass-walled office tower on the edge of downtown Buenos Aires, just a few hundred feet from the old port district. In the crowded elevator, he shook his head and muttered under his breath about the stresses of the day and his profession. “I swear, this job can kill me,” he said, his eyes cast downward.

On the 20th floor, he hustled into an impersonal, windowless office and quickly removed the tools of his trade from his backpack and set them on the desk: locked blue cash box, cellphone and clunky Dell laptop with the same yellow smiley-face sticker that he puts on all his electronics. Then he unbuckled the fanny pack from around his waist, which contained the most important part of his business: bricks of $100 bills and 100-peso notes.

This room, rented for the day, was not one of Castiglione’s regular haunts. He mostly drifts among the old cafes in Buenos Aires, where the bow-tie-wearing waiters serve small glasses of seltzer water with each coffee. In his line of business as a money-changer, temporary meeting places are preferred; they make things harder for would-be thieves, whom he has so far avoided. On this Friday in late February, Castiglione had run around the city in his camouflage-patterned sandals, trying to distribute cash to some clients and pick it up from others. Once back in his temporary office, his outdated LG phone alternately chirped, buzzed and sang with incoming text messages and emails.

Ordinarily, Castiglione would have help. His 18-year-old daughter, Fiona, often deals with customers, but she was about to give birth to her first child. Her twin brother, Marco, who used to make cash runs, was now focusing on school. So Castiglione was alone, his stress evident in the sweat on his forehead and the agitation on his face. When his business partner, who lives in Rosario, Argentina’s third-largest city, called to ask why he hadn’t taken care of one particularly insistent client, Castiglione erupted in frustration.

“If you want it done faster, you pick up the phone and call her yourself,” he growled in Spanish, before switching to another call.

After hanging up, he told me in English: “Everybody wants everything now, and I am just trying to do it. I’m not magical, as people think.”

Magical, no, yet something new all the same. His occupation is one of the world’s oldest, but it remains a conspicuous part of modern life in Argentina: Calle Florida, one of the main streets in downtown Buenos Aires, is crowded day and night with men and women singing out “cambio, cambio, cambio, casa de cambio,” to serve local residents who want to trade volatile pesos for more stable and transportable currencies like the dollar. For Castiglione, however, money-changing means converting pesos and dollars into Bitcoin, a virtual currency, and vice versa.

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Llallawavis scagliai: a new Mesembriornithinae Terror Bird From Pliocene Neogene Argentina had Good Eyesight, but not as Good Hearing

A new Mesembriornithinae (Aves, Phorusrhacidae) provides new insights into the phylogeny and sensory capabilities of terror birds

Authors:

Degrange et al

Abstract:

Terror birds constitute the most outstanding group of the South American Cenozoic avifauna. Considered as apex predators, their hunting skills have recently been examined, but their diversity is still unresolved. Here we report a new terror bird from the late Pliocene of Argentina, represented by the most complete articulated skeleton of one yet found. Our phylogenetic analysis places this taxon among derived phorusrhacids (Mesembriornithinae). One of the most striking cranial features of the new species is the suppression of intracranial kinesis due to the presence of an independent ossified bone that increases the structural link between the lacrimal and jugal bars, and the absence of both palatal hinges. The new species possesses ossified tracheal rings and a tracheobronchial syrinx, as well as sclerotic ossicles to adjust the shape of the cornea during its diurnal vision, and reveals a mean hearing sensitivity (~2300 Hz) below the average for living species. The discovery of this new species provides new insights for studying the anatomy and phylogeny of phorusrhacids and a better understanding of this group's diversification.

An Impressive Hegetothere Notoungulate Assemblage from Oligocene Paleogene Argentina

The Hegetotheriidae (Mammalia, Notoungulata) assemblage from the late Oligocene of Mendoza, central-western Argentina

Authors:

Cerdeño et al

Abstract:

This study describes new remains of Hegetotheriidae (Notoungulata), including a new species, from the Deseadan (late Oligocene) of Quebrada Fiera, Mendoza Province, Argentina. The assemblage is composed of four hegetotheriines, Prohegetotherium cf. P. sculptum, Prohegetotherium sp., Prohegetotherium schiaffinoi, and Prohegetotherium malalhuense, sp. nov., and the pachyrukhine Propachyrucos cf. P. simpsoni. The presence of Prosotherium cannot be totally discounted because lower molariforms are rather similar between the two pachyrukhine genera. The new species Prohegetotherium malalhuense, sp. nov., differs from all previously described hegetotheriines by having a lingually projecting, sharp parastyle and marked parastyle groove on the ectoloph of M2–3; talonid of m1–2 posterolabially projected; talonid of m3 with marked posterolabial groove; and the smaller size. Its phylogenetic affinities are not well resolved. Prohegetotherium is paraphyletic, with P. sculptum sister taxon to the remaining hegetotheres, and the new taxon more closely related to Hegetotherium mirabile than to P. schiaffinoi. The recognition of P. schiaffinoi and Prohegetotherium cf. P. sculptum emphasizes that the fauna from Quebrada Fiera shares elements with roughly contemporaneous Deseadan faunas from northern and southern latitudes, but important faunal particularities distinguish the region as well. The record of pachyrukhines at Quebrada Fiera more closely resembles Deseadan faunas in Patagonia than temporally correlative faunas from Bolivia and Uruguay, and indicates the presence of suitable habitats in mid-latitudes of Argentina for this hypselodont clade. Faunal affinities together with particular taxa from Quebrada Fiera appear to support a significant faunal provinciality in South America during the late Oligocene.

First Genetically Adapted Population of Humans Tolerant of Arsenic Found

High up in the high Andes mountains of Argentina, researchers have identified the first-ever evidence of a population uniquely adapted to tolerate the toxic chemical arsenic.

For thousands of years, in some regions of the Andes, people have been exposed to high levels of arsenic, a naturally occurring phenomenon that happens when arsenic in the volcanic bedrock is released into the groundwater. How could this population adapt to tolerate arsenic, a potent killer of such ill repute that it's often the overused plot-driver of many murder mysteries?

In a new study published in the advanced online edition of Molecular Biology and Evolution, a Swedish research team led by Karolinska Institutet and Uppsala University professor Karin Broberg, performed a genome wide survey from a group of 124 Andean women screened for the ability to metabolize arsenic (measured by levels in the urine). The study pinpointed a key set of nucleotide variants in a gene, AS3MT, which were at much lower frequencies in control populations from Columbia and Peru. The researchers estimate that the increase in frequency of these variants occurred recently, between 10,000-7,000 years ago, based on the age of a recently excavated mummy that was found to have high arsenic levels in its hair.

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Purranisaurus potens: a Very Strange Metriorhynchid Thalattosaur From Tithonian Jurassic/Berriasian Cretaceous Patagonia

Purranisaurus potens Rusconi, an enigmatic metriorhynchid from the Late Jurassic–Early Cretaceous of the Neuquén Basin

Authors:

Herrera et al

Abstract:

The Tithonian record from northwestern Patagonia (Neuquén Basin) documents a complete succession of lower, middle, and late Tithonian marine reptiles. From the late Tithonian–early Berriasian of Patagonia, three marine crocodyliforms have been recorded: Dakosaurus andiniensis, Cricosaurus araucanensis, and Purranisaurus potens. Although P. potens includes the first metriorhynchid skull described from Patagonia, no detailed description and/or illustrations have been published. Since the mid-20th century, several authors have discussed the validity of P. potens. Recent preparation of the type material allowed a detailed description as well as exploration of its phylogenetic relationships. We consider P. potens as a valid taxon characterized by a unique combination of characters, such as medial and posterolateral processes of the frontal forming an angle of 60°; supratemporal fossae reaching the minimum interorbital distance, with the dorsal margin of the supratemporal arch being slightly concave in lateral view; thin bony lamina projecting from the lateral and medial alveolar margins of the maxilla; occipital surface ventral to occipital condyle parallel to transverse plane of skull; well-developed crest that extends along the entire height of the supraoccipital; and orbital process of the quadrate very conspicuous and acute, horizontal, and without bony attachment. Phylogenetic analysis recovers P. potens as deeply nested within Geosaurini and, contrary to previous proposals, not closely related to ‘Metriorhynchus’ casamiquelai and ‘M.’ westermanni. Internal relationships within Geosaurini are unresolved. Purranisaurus, as a monotypic genus, is restricted to the late Tithonian–early Berriasian.

A Finer Resolution Timeline for the South American Megafauna Component of the Sixth Mass Extinction

Megafauna Extinction in South America: A new chronology for the Argentine Pampas

Authors:

Prado et al

Abstract:

The megafauna extinction in South America was one of the most profound events, with the loss of 50 genera (~ 83%). Three orders disappeared (Notoungulata, Proboscidea, Litopterna), as did all large xenarthrans, but how this fits into global extinction is uncertain, mainly due to the lack of chronological resolution. In recent years there has been an increase in the number of radiocarbon dating at archaeological and paleontological sites, but this information varies greatly from area to area in South America, and few data can be considered to constitute a taxon-date.

The timing of the late Pleistocene extinction in the Pampas is poorly established. Most taxa only appear in the biostratigraphic context and many reported 14C dates do not meet rigorous criteria for accepting dates, including reports suggesting survival of megafauna into the Holocene. In the present paper, we evaluate the published radiocarbon dates in the pampas and present 20 new radiocarbon dates for paleontological sites in order to establish a more accurate “extinction window” for the key taxa. These new dates are sufficiently robust to assess correspondences among last-appearance records of megafauna, first-appearance records of humans, and the Younger Dryas to Holocene climatic transition in the Argentine Pampas. These results highlight the need for greater effort in taxa selection for dating.

Giant Sloth Megatherichnum Trackway From Miocene Neogene Argentina is NOT Bipedal

Late Miocene ground sloth footprints and their palaeoenvironment: Megatherichnum oportoi revisited

Authors:

Melchor et al

Abstract:

Fossil footprints of ground sloths are mostly restricted to the late Miocene to Pleistocene of South America. This study is focused on the oldest known ground sloth trackways, Megatherichnum oportoi Casamiquela, 1974 from the late Miocene Río Negro Formation of northern Patagonia. The section logged at the study site, near Carmen de Patagones (Buenos Aires province), includes the uppermost part of the middle member (marine) and the upper member (aeolian) of the Río Negro Formation. Identified sedimentary facies can be grouped into four facies associations: tidal flat, aeolian dune, dry/damp interdune and wet interdune (shallow lacustrine). M. oportoi trackways are preserved in an upper intertidal mixed flat. Associated trace fossils belong to a wet aeolian system developed close to the sea coast and were mostly preserved in interdune facies. These include Poaceae root and stem traces and Nagtuichnus meuleni (Chlamyphorinae burrow) in dry interdune facies, indeterminate tetrapod footprints in damp interdune facies, Lockeia siliquaria and chevron-like trace fossils (bivalve resting and horizontal locomotion traces) in wet interdune facies (shallow lakes), and Palaeophycus tubularis in aeolian dune facies. The most likely trackmaker of M. oportoi is Pyramiodontherium sp. (Megatheriinae), recorded from the same stratigraphic unit at Chubut province, with a body mass ranging from 2.5 to 3.6 tonnes. M. oportoi is interpreted as a quadrupedal trackway of a late Miocene ground sloth without overlap of the pes on the manus. The previously proposed bipedal interpretation for the trackway requires angles of gait in excess of those permitted for such a large and heavy animal. Pleistocene ground sloth trackways are distinctive because of the much smaller size of the fore footprint. For the latter examples, a quadrupedal locomotion with overlap of the pes on the manus may be applied.

China is Interested in Selling the J-10B to Argentina

The "Chengdu FC-1 is a light fighter developed by the Chengdu Aircraft Industry Co., Ltd specifically for the market in the third world countries. Its advantages include a high performance-price ratio, with a unit price of only more than 30 million U.S. dollars," said Xu Yongling, China’s meritorious test pilot of J-10 and air force theory expert.

　　However, Xu Yongling also pointed out that the Chengdu FC-1 originated from J-7 after all, it is not a fourth-generation warplane in a strict sense, thus with relatively low operational effectiveness.

　　Britain now deploys six "Typhoon" fighters in the Malvinas (Falkland) Islands, while four "Typhoon" fighters four or five years ago. Once the situation becomes tense, or simply if Argentina upgrades its air force equipment, the Britain may keep sending its "Typhoon" fighters or even E-3 early warning airplanes along the route of "mainland Britain-Gibraltar-Ascension Island- Malvinas (Falkland) Island" at any time.

　　"14 FC-1 fighters seem to have quantitative superiority over six Typhoon fighters, but the Britain can absolutely deploy one or two squadrons of Typhoon fighters and early warning airplanes in the Malvinas (Falkland) Island." In the eyes of Xu Yongling, the introduction of FC-1 actually doesn’t substantially help improve the situation in the Malvinas (Falkland) Island since there is no quantitative superiority and the single-aircraft combat capability is obviously inferior. "Even if less money is spent compared to that for J-10, it is a waste," said Xu.

　　Only J-10B can contend against "Typhoon"

　　If Argentina possesses the new-type J-10B which is also a fourth-and-a-half-generation fighter and equipped with the phased-array radar, it is completely capable of fighting the "Typhoon" fighter because the latter is using the traditional pulsed Doppler radar.

　　With the advanced navigation-power equipment that reaches the level for fifth-generation warplanes, the J-10B can also carry the China-made air-to-air missiles that reach the world's top level -- including the active radar guided medium-range missile PL-12 and infrared imaging guided fighting missile PL-10 which are no way inferior to the America-made medium-range missile AIM-120 and "Sidewinder" fighting missile.

　　If the J-10 is deployed in the Malvinas (Falkland) Island direction, its limited combat radius is worrying, because after all the Malvinas (Falkland) Island is 500 kilometers away from the mainland of Argentina. But the J-10B has the flight-refuel function, and this is not a big problem if the refueling aircraft is also introduced.

　　"Facing the Britain, a traditional powerful nation, as well as the surrounding countries such as Chile and Brazil which have introduced fourth-generation warplanes, Argentina would feel ashamed for the old stuffs it is using," Xu Yongling said that the F-16 fighters Chile bought from America were delivered in 2008. At present, Chile has 46 F-16 fighters, one Israeli "Vulture" early warning airplane, and three KC-135 refueling aircraft. Brazil signed the agreement with Sweden last year to buy 108 "Gripen" fighters, and the first batch of 28 such fighters will be delivered in 2019.

　　In such grim strategic environment, Argentina has to choose the equipment of the same level -- the new model of J-10, in order to have the freedom of choice and leeway. Once the production lines for fighters and ammunition are introduced, Argentina will be able to produce advanced fighters endlessly, making the cost of delivering combat forces from the mainland of Britain too high to bear, no matter the land-based aviation forces or aircraft carrier taskforce.

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