Negative-Pressure Wound Therapy for the Management of Complex Surgical Wounds in a Minority Population.

Introduction Negative-pressure wound therapy (NPWT) has been used for decades as an established treatment modality for complex wounds, now commonplace in hospitals and various clinical and outpatient settings. Several studies have noted improved healing outcomes with this device, but the current state of literature is in debate on both clinical and economic effectiveness. The use of NPWT can become expensive, largely because of the complexity of wounds and the need for outpatient management, from which a majority of the benefit is derived. This creates a disparity in access to this therapy. A lack of insurance and limited access to healthcare that is present in minority populations contribute to this inequality. Methods We reviewed the clinical courses of eight patients who were treated with NPWT at a single acute care facility in an underserved area caring for a minority population. Results We describe several different anatomic wounds along with details including the size of wounds, number of debridements, length of hospital stay, duration of treatment, and ensuing courses of the minority patients who received NPWT for the entire duration of their wound care course. Conclusions This case series demonstrates desirable wound healing outcomes with the use of NPWT in the minority population. The authors draw attention to the outpatient benefit of this device that may be lost in those with limited insurance in minority populations and seek to encourage further studies in this population in resource-limited settings to determine its true clinical effectiveness.

A large therian mammal from the Late Cretaceous of South America.

Theria represent an extant clade that comprises placental and marsupial mammals. Here we report on the discovery of a new Late Cretaceous mammal from southern Patagonia, Patagomaia chainko gen. et sp. nov., represented by hindlimb and pelvic elements with unambiguous therian features. We estimate Patagomaia chainko attained a body mass of 14 kg, which is considerably greater than the 5 kg maximum body mass of coeval Laurasian therians. This new discovery demonstrates that Gondwanan therian mammals acquired large body size by the Late Cretaceous, preceding their Laurasian relatives, which remained small-bodied until the beginning of the Cenozoic. Patagomaia supports the view that the Southern Hemisphere was a cradle for the evolution of modern mammalian clades, alongside non-therian extinct groups such as meridiolestidans, gondwanatherians and monotremes.

Comments on the pelvic girdle anatomy of Lagerpeton chanarensis Romer, 1971 (Archosauria) and its implications on the posture and gait of early pterosauromorphs.

Lagerpeton chanarensis is an early avemetatarsalian from the lower Carnian (lowermost Upper Triassic) levels of the Chañares Formation, La Rioja Province, Argentina. Lagerpeton and its kin were traditionally interpreted as dinosaur precursors of cursorial habits, with a bipedal posture and parasagittal gait. Some authors also speculated saltatorial capabilities for this genus. Recent analyses indicate that lagerpetids are early-diverging pterosauromorphs, a hypothesis that invites a review of most aspects of their anatomy and function. A revision of available specimens and additional preparation of previously known individuals indicate that Lagerpeton lacked a parasagittal gait and was probably a sprawling archosaur. This latter inference is based on the femoral head articulation with the acetabulum. The acetabular rim has a strongly laterally projected posteroventral antitrochanteric corner, which results in a position of the legs that recalls that of sprawling living reptiles, such as lizards, and departs from the parasagittally positioned limbs of dinosaurs. This may indicate that early pterosauromorphs had a sprawling posture of their hindlegs, casting doubts on the significance of bipedal posture and parasagittal gait for the radiation of early ornithodirans, given that both traits have been regarded as key features that triggered the ecological and evolutionary success of the clade. Our results bolster recent claims of a high ecomorphological diversity among early avemetatarsalians.

A Maastrichtian insect assemblage from Patagonia sheds light on arthropod diversity previous to the K/Pg event.

Insect faunas from the latest Cretaceous are poorly known worldwide. Particularly, in the Southern Hemisphere, there is a gap regarding insect assemblages in the Campanian-Maastrichtian interval. Here we present an insect assemblage from the Maastrichtian Chorrillo Formation, southern Argentina, represented by well-preserved and non-deformed, chitinous microscopic remains including head capsules, wings and scales. Identified clades include Chironomidae dipterans, Coelolepida lepidopterans, and Ephemeroptera. The assemblage taxonomically resembles those of Cenozoic age, rather than other Mesozoic assemblages, in being composed by diverse chironomids and lepidopterans. To the best of our knowledge, present discovery constitutes the first insect body fossils for the Maastrichtian in the Southern Hemisphere, thus filling the gap between well-known Early Cretaceous entomofaunas and those of Paleogene age. The presented evidence shows that modern clades of chironomids were already dominant and diversified by the end of the Cretaceous, in concert with the parallel radiation of aquatic angiosperms which became dominant in freshwater habitats. This exceptional finding encourages the active search of microscopic remains of fossil arthropods in other geological units, which could provide a unique way of enhancing our knowledge on the past diversity of the clade.

New reptile shows dinosaurs and pterosaurs evolved among diverse precursors.

Dinosaurs and pterosaurs have remarkable diversity and disparity through most of the Mesozoic Era1-3. Soon after their origins, these reptiles diversified into a number of long-lived lineages, evolved unprecedented ecologies (for example, flying, large herbivorous forms) and spread across Pangaea4,5. Recent discoveries of dinosaur and pterosaur precursors6-10 demonstrated that these animals were also speciose and widespread, but those precursors have few if any well-preserved skulls, hands and associated skeletons11,12. Here we present a well-preserved partial skeleton (Upper Triassic, Brazil) of the new lagerpetid Venetoraptor gassenae gen. et sp. nov. that offers a more comprehensive look into the skull and ecology of one of these precursors. Its skull has a sharp, raptorial-like beak, preceding that of dinosaurs by around 80 million years, and a large hand with long, trenchant claws that firmly establishes the loss of obligatory quadrupedalism in these precursor lineages. Combining anatomical information of the new species with other dinosaur and pterosaur precursors shows that morphological disparity of precursors resembles that of Triassic pterosaurs and exceeds that of Triassic dinosaurs. Thus, the 'success' of pterosaurs and dinosaurs was a result of differential survival among a broader pool of ecomorphological variation. Our results show that the morphological diversity of ornithodirans started to flourish among early-diverging lineages and not only after the origins of dinosaurs and pterosaurs.

First monotreme from the Late Cretaceous of South America.

Monotremata is a clade of egg-lying mammals, represented by the living platypus and echidnas, which is endemic to Australia, and adjacent islands. Occurrence of basal monotremes in the Early Cretaceous of Australia has led to the consensus that this clade originated on that continent, arriving later to South America. Here we report on the discovery of a Late Cretaceous monotreme from southern Argentina, demonstrating that monotremes were present in circumpolar regions by the end of the Mesozoic, and that their distinctive anatomical features were probably present in these ancient forms as well.

Neurogenic Lower Urinary Tract Dysfunction in Asymptomatic Patients with Multiple Sclerosis.

Neurogenic lower urinary tract dysfunction (NLUTD) in asymptomatic patients with MS has been described in preliminary studies, but specific investigations of this topic are rare. Many authors advise early diagnosis and treatment of NLUTD in patients with MS. In contrast, clinical practice and different guidelines recommend neuro-urological diagnostics only in the presence of symptoms. Our aim was to investigate the characteristics of NLUTD and the correlations of clinical parameters with NLUTD in asymptomatic patients with MS. We evaluated bladder diaries, urodynamic findings, and therapy proposals. Correlations of the voided volume, voiding frequency, urinary tract infections, and uroflowmetry including post-void residual with the urodynamic findings were determined. In our study, 26% of the patients were asymptomatic. Of these, 73.7% had urodynamic findings indicative of NLUTD, 21.1% had detrusor overactivity, 13.2% had detrusor underactivity, 13.2% detrusor overactivity and detrusor sphincter dyssynergia, and 57.9% had radiologically abnormal findings of the bladder. No patients presented low bladder compliance or renal reflux. Clinical parameters from the bladder diary and urinary tract infections were found to be correlated with NLUTD, and the absence of symptoms did not exclude NLUTD in patients with MS. We observed that urinary tract damage is already present in a relevant proportion. Based on our results, we recommend that patients with MS be screened for NLUTD regardless of the subjective presence of urinary symptoms or the disease stage.

Evaluación del Orbit Bleeding Risk Score como predictor de sangrado mayor en pacientes con síndrome coronario agudo / Evaluation of the Orbit Bleeding Risk Score as Predictor of Major Bleeding in Patients with Acute Coronary Syndrome

RESUMEN Introducción: El sangrado mayor es la complicación más importante del tratamiento antitrombótico en el síndrome coronario agudo (SCA), y se asocia a mayor mortalidad. Evaluar el riesgo de sangrado es un desafío. La utilidad del Orbit Bleeding score (ORBIT) para evaluar el riesgo de sangrado en SCA ha sido poco estudiada. Objetivo: Evaluar al ORBIT como predictor de sangrado mayor en pacientes internados por SCA en los que se decide la anticoagulación como parte de la estrategia antitrombótica. Materiales y métodos: Se incluyeron en forma retrospectiva pacientes internados en dos unidades coronarias con diagnóstico de SCA que recibieron anticoagulación como parte de la terapia antitrombótica. A todos se les calcularon los scores CRUSADE, ACTION-GWTG y ORBIT con los datos clínicos del ingreso. Se analizo el punto primario de sangrado mayor, definido como una clasificación de BARC 3 o 5. Resultados: Se incluyeron 762 pacientes. El sangrado mayor se presentó en el 3.4%. En el análisis univariado los tres scores fueron predictores de sangrado mayor, mientras que en el multivariado sólo el ORBIT fue predictor independiente de sangrado mayor, con OR 2,46, IC95% 1,61-3,97, p <0,001. El área bajo la curva ROC fue de 0,70, 0,68 y 0,80 para los scores ACTIONGWTG, CRUSADE y ORBIT, respectivamente. El ORBIT presento una mayor área bajo la curva que el CRUSADE (p = 0,03) sin diferencias significativas con el ACTION-GWTG (p = 0,06) Conclusiones: El ORBIT fue el único predictor independiente de sangrado mayor, con una mejor capacidad de discriminación que el CRUSADE, y tendencia a mejor capacidad que el ACTION-GWTG.

ABSTRACT Background: Major bleeding is the most important complication of antithrombotic treatment in acute coronary syndrome (ACS) and is associated with higher mortality. Assessing the risk of bleeding is a challenge. The usefulness of the Orbit Bleeding Score (ORBIT) to assess the risk of bleeding in ACS has been scarcely studied. Objective: The aim of this study was to evaluate the ORBIT score as a predictor of major bleeding in patients hospitalized for ACS in whom anticoagulation is decided as part of the antithrombotic strategy. Methods: Patients admitted to two coronary care units with diagnosis of ACS who received anticoagulation as part of the antithrombotic therapy were retrospectively included in the study. The CRUSADE, ACTION-GWTG and ORBIT scores were calculated using the admission clinical data. The primary endpoint was major bleeding, defined as BARC 3 or 5 classification. Results: The study included 762 patients. Major bleeding occurred in 3.4% of cases. In the univariate analysis, the three scores were predictors of major bleeding, while in the multivariate analysis only the ORBIT score was an independent predictor of major bleeding (OR: 2.46, 95% CI 1.61-3.97, p <0.001). The area under the ROC curve was 0.70, 0.68 and 0.80 for the ACTION-GWTG, CRUSADE and ORBIT scores, respectively. The ORBIT score presented a higher area under the curve than the CRUSADE score (p=0.03) but without significant difference with the ACTION-GWTG score (p=0.06) Conclusions: The ORBIT score was the only independent predictor of major bleeding, presenting a better discrimination capacity than the CRUSADE score and a tendency to better capacity than the ACTION-GWTG score.

Wing osteology, myology, and function of Rhea americana (Aves, Rheidae).

The Greater Rhea (Rhea americana, Rheidae) is a flightless paleognath with a wide geographical distribution in South America. The morphology of its shoulder girdle and wings are different from those of flying birds and some characteristics are similar to basal birds and paravian theropods. We present a detailed osteological, myological, and functional study of the shoulder and the wing of the Greater Rhea. Particular features of the anatomy of the pectoral girdle and wing of Rhea include the lack of triosseal canal, reduced origin area of the mm. pectoralis p. thoracica and supracoracoideus and the lack of a propatagium. The wing muscle mass is markedly reduced, reaching only 0.89% of total body mass (BM). Forelimb muscles mass values are low compared to those of flying birds and are congruent with the non-use of wings for active locomotion movements. R. americana does not flap the wings dorso-ventral as typical for flying birds, but predominantly in cranio-caudal direction, following a craniolateral to caudomedial abduction-adduction arc. When the wings are fully abducted, they are inverted L-shaped, with the inner surface caudally faced, and when the wings are folded against the body, they do not perform the complete automatic wing folding nor the circumduction of the manus, a movement performed by extant volant birds. This study complements our knowledge of the axial musculature of the flightless paleognaths and highlights the use of the Greater Rhea as a model, which may help understand the evolution of Palaeognathae, as well as the origin of flapping flight among paravian theropods.

A large Megaraptoridae (Theropoda: Coelurosauria) from Upper Cretaceous (Maastrichtian) of Patagonia, Argentina.

Megaraptora is a theropod clade known from former Gondwana landmasses and Asia. Most members of the clade are known from the Early to Late Cretaceous (Barremian-Santonian), with Maastrichtian megaraptorans known only from isolated and poorly informative remains. The aim of the present contribution is to describe a partial skeleton of a megaraptorid from Maastrichtian beds in Santa Cruz Province, Argentina. This new specimen is the most informative megaraptoran known from Maastrichtian age, and is herein described as a new taxon. Phylogenetic analysis nested the new taxon together with other South American megaraptorans in a monophyletic clade, whereas Australian and Asian members constitute successive stem groups. South American forms differ from more basal megaraptorans in several anatomical features and in being much larger and more robustly built.

Distinct tumor-infiltrating lymphocyte landscapes are associated with clinical outcomes in localized non-small-cell lung cancer.

BACKGROUND: Despite the importance of tumor-infiltrating T lymphocytes (TILs) in cancer biology, the relationship between TIL phenotypes and their prognostic relevance for localized non-small-cell lung cancer (NSCLC) has not been well established. PATIENTS AND METHODS: Fresh tumor and normal adjacent tissue was prospectively collected from 150 patients with localized NSCLC. Tissue was comprehensively characterized by high-dimensional flow cytometry of TILs integrated with immunogenomic data from multiplex immunofluorescence, T-cell receptor sequencing, exome sequencing, RNA sequencing, targeted proteomics, and clinicopathologic features. RESULTS: While neither the magnitude of TIL infiltration nor specific TIL subsets were significantly prognostic alone, the integration of high-dimensional flow cytometry data identified two major immunotypes (IM1 and IM2) that were predictive of recurrence-free survival independent of clinical characteristics. IM2 was associated with poor prognosis and characterized by the presence of proliferating TILs expressing cluster of differentiation 103, programmed cell death protein 1, T-cell immunoglobulin and mucin-domain containing protein 3, and inducible T-cell costimulator. Conversely, IM1 was associated with good prognosis and differentiated by an abundance of CD8+ T cells expressing cytolytic enzymes, CD4+ T cells lacking the expression of inhibitory receptors, and increased levels of B-cell infiltrates and tertiary lymphoid structures. While increased B-cell infiltration was associated with good prognosis, the best prognosis was observed in patients with tumors exhibiting high levels of both B cells and T cells. These findings were validated in patient tumors from The Cancer Genome Atlas. CONCLUSIONS: Our study suggests that although the number of infiltrating T cells is not associated with patient survival, the nature of the infiltrating T cells, resolved in distinct TIL immunotypes, is prognostically relevant in NSCLC and may inform therapeutic approaches to clinical care.

Fossil fishes and anurans from the Miocene of Rio Chico and Cerro Zeballos, Chubut Province, Argentina.

The fossil record of freshwater fishes and anurans from the Miocene in Patagonia is relatively patchy, a large number of specimens remaining undescribed. The aim of the present contribution is to describe a fossil association of percomorphacean fishes and calyptocephalellid anurans from the early to late Miocene Collón Curá Formation, at Chubut province, Patagonia, Argentina. In spite of being represented by several specimens, both anurans and fishes show a very low taxonomic diversity. This pattern matches with other fossil sites from the Cenozoic of Patagonia, as well as with the extant Patagonian batrachofaunas and ichthyofaunas. The fossil record of frogs and fishes in Patagonia is represented by few lineages that have a large evolutionary history in the area, and occasionally can be traced up to the Late Mesozoic.

Rapidly progressive aortic stenosis treated with transcatheter aortic valve implantation in a patient with Fabry disease: a case report.

BACKGROUND: Fabry disease (FD) is a rare lysosomal storage disease, caused by mutations in the gene encoding the enzyme α-galactosidase A (α-Gal A). Cardiac involvement is one of the main causes of death and it is characterized by progressive concentric left ventricular hypertrophy (LVH), which in most cases is symmetric. Mild thickening of the left-sided valves is seen in as many as a quarter of patients. Severe aortic stenosis is an extremely rare disorder in FD. CASE SUMMARY: In this report, we describe the case of a 57-year-old male, who was diagnosed with a cardiac variant of FD 10 years ago. Since the patient had severe LVH, he was started on enzyme replacement therapy when he was 47 years old with an intravenous infusion of 0.2 mg/kg of agalsidase alpha every 14 days. The patient remained stable and asymptomatic for 9 years, until he presented with dyspnoea in New York Heart Association functional class II-III and severe aortic stenosis (aortic valve area: 0.97 cm2) together with severe systolic dysfunction [ejection fraction (EF): 29%]. Because of the patient's comorbidities and high surgical risk, he underwent successful transfemoral transcatheter aortic valve implantation (TAVI). At 2 months following TAVI, the patient was asymptomatic and, in spite of his Fabry cardiomyopathy, the EF had increased to 45%. DISCUSSION: To our knowledge, this is the first case in the literature to demonstrate a rapid progression of aortic stenosis with severe impairment of left ventricular function and worsening in functional class in a patient with FD, who following TAVI improved his EF, with disappearance of symptoms and ventricular arrhythmias.

New transitional fossil from late Jurassic of Chile sheds light on the origin of modern crocodiles.

We describe the basal mesoeucrocodylian Burkesuchus mallingrandensis nov. gen. et sp., from the Upper Jurassic (Tithonian) Toqui Formation of southern Chile. The new taxon constitutes one of the few records of non-pelagic Jurassic crocodyliforms for the entire South American continent. Burkesuchus was found on the same levels that yielded titanosauriform and diplodocoid sauropods and the herbivore theropod Chilesaurus diegosuarezi, thus expanding the taxonomic composition of currently poorly known Jurassic reptilian faunas from Patagonia. Burkesuchus was a small-sized crocodyliform (estimated length 70 cm), with a cranium that is dorsoventrally depressed and transversely wide posteriorly and distinguished by a posteroventrally flexed wing-like squamosal. A well-defined longitudinal groove runs along the lateral edge of the postorbital and squamosal, indicative of a anteroposteriorly extensive upper earlid. Phylogenetic analysis supports Burkesuchus as a basal member of Mesoeucrocodylia. This new discovery expands the meagre record of non-pelagic representatives of this clade for the Jurassic Period, and together with Batrachomimus, from Upper Jurassic beds of Brazil, supports the idea that South America represented a cradle for the evolution of derived crocodyliforms during the Late Jurassic.

Osteology of Unenlagia comahuensis (Theropoda, Paraves, Unenlagiidae) from the Late Cretaceous of Patagonia.

Unenlagia comahuensis was originally described as a phylogenetic link between nonavian dinosaurs and birds. Later it was interpreted by some authors as belonging to the deinonychosaurian clade Dromaeosauridae, and more recently as phylogenetically closer to birds than to dromaeosaurids. The only known specimen is represented by an incomplete skeleton, including vertebrae, incomplete scapular girdle, pelvis, and limbs, coming from Upper Cretaceous beds of Neuquén province, Patagonia, Argentina. The aim of the present paper is to include a detailed anatomical description of Unenlagia (currently only known by preliminary descriptions). Detailed analysis of Unenlagia anatomy resulted in the recognition of one possible additional Unenlagiidae synapomorphy (i.e., the presence of cup-like iliac articulation on ischium). We recognize derived anatomical traits that Unenlagia and kin share with birds, lending support to the interpretation that unenlagiids are stem-Avialae. Particularly, some appendicular features (e.g., scapula with subtriangular and relatively reduced acromion, poor outward projection of the glenoid and glenoidal lips on the scapula, lateral orientation of scapular glenoid, craniolaterally oriented deltopectoral crest of humerus) may be related to the acquisition of anatomical novelties that in birds are associated with flight. The present contribution on Unenlagia provides new data regarding the early evolution of avian features.

Behavioral Changes After the COVID-19 Lockdown in Italy.

This study aims at identifying the tools necessary for COVID-19 health emergency management, with particular reference to the period following the first lockdown, a crucial phase in which it was important to favor the maintenance of protective behaviors. It also aims at identifying the messages and sources that were most effective in managing communication correctly in such a crucial phase that is likely characterized by a fall in perceived health risk (due to the flattening of the epidemic curve) and a simultaneous rise in perceived economic and social risks (due to the enduring calamity). Knowing what source will be most effective to convey a specific message is fundamental in enabling individuals to focus on and comply with the rules. At the same time, it is necessary to understand how the message should be presented, and the relationships between messages, sources and targets. To meet these goals, data were collected through a self-administered online questionnaire submitted to a sample of undergraduate students from a University in Lombardy-the region most affected by the pandemic in the first wave- (Study 1), and to a national sample composed of Italian citizens (Study 2). Through our first manipulation which explored the effectiveness of social norms in relation to different sources, we found that, in the national sample, the injunctive norm conveyed by the government was the most effective in promoting behavioral intentions. By contrast, among the students, results showed that for the critical group with a lower risk perception (less inclined to adopt prevention behavior) descriptive norms, which implicitly convey the risk perception of peers, were as effective as the government injunctive norm. Our second manipulation, identical in Study 1 and 2, compared four types of communication (emotional, exponential growth, both of them, or neutral). The neutral condition was the most memorable, but no condition was more effective than the others. Across all message types there was a high intention to adopt protective behaviors. The results indicate possible applicative implications of the adopted communicative tools.

Overactive bladder syndrome - focus onto detrusor overactivity.

INTRODUCTION AND HYPOTHESIS: To determine in patients with overactive bladder (OAB), urodynamic differences as well to compare the characteristics of patient's, with presence of detrusor overactivity on urodynamics with those with absence of detrusor overactivity. METHODS: Taking into account the urodynamic findings, the patients with OAB symptoms were categorized into one of two groups: group 1 (with detrusor overactivity) or group 2 (without detrusor overactivity), and comparative analyses for both groups were performed (epidemiological data, patient history, urodynamic criteria, bladder diaries, IC-OAB, IC-OABqol - questionnaires). RESULTS: There was a significant difference in age as well in the disease duration between group 1 and group 2. Although the mean number of micturitions and nocturia episodes was comparable, the numbers of urgency episodes differed significantly. The number of 'wet' patients was significantly higher in the group 1 with the significantly higher number of incontinence episodes. Group 1 demonstrated higher OAB symptom scores and higher impact on the patients' quality of life. CONCLUSIONS: More than half of the patients complaining of urgency-frequency do not have detrusor overactivity upon urodynamic testing, and only half have detrusor overactivity that correlates with urge perception. The patients with no detrusor overactivity appear to be significantly younger and have fewer symptoms, with a less pronounced impact on quality of life. They also have significantly higher maximal bladder capacity. This data supports the hypothesis that both conditions are different phases (early and late) of the same pathological state, or may be two different subtypes of OAB.

Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria.

Pterosaurs were the first vertebrates to evolve powered flight1 and comprised one of the main evolutionary radiations in terrestrial ecosystems of the Mesozoic era (approximately 252-66 million years ago), but their origin has remained an unresolved enigma in palaeontology since the nineteenth century2-4. These flying reptiles have been hypothesized to be the close relatives of a wide variety of reptilian clades, including dinosaur relatives2-8, and there is still a major morphological gap between those forms and the oldest, unambiguous pterosaurs from the Upper Triassic series. Here, using recent discoveries of well-preserved cranial remains, microcomputed tomography scans of fragile skull bones (jaws, skull roofs and braincases) and reliably associated postcrania, we demonstrate that lagerpetids-a group of cursorial, non-volant dinosaur precursors-are the sister group of pterosaurs, sharing numerous synapomorphies across the entire skeleton. This finding substantially shortens the temporal and morphological gap between the oldest pterosaurs and their closest relatives and simultaneously strengthens the evidence that pterosaurs belong to the avian line of archosaurs. Neuroanatomical features related to the enhanced sensory abilities of pterosaurs9 are already present in lagerpetids, which indicates that these features evolved before flight. Our evidence illuminates the first steps of the assembly of the pterosaur body plan, whose conquest of aerial space represents a remarkable morphofunctional innovation in vertebrate evolution.

New record of a Mesozoic gondwanatherian mammaliaform from Southern Patagonia.

Gondwanatheria is an enigmatic mammaliaform clade distributed in the Cretaceous and Paleogene of South America, Africa, Madagascar, India and Antarctica. The Mesozoic record in South America is restricted to the Latest Cretaceous of Río Negro and Chubut provinces, Argentina and Magallanes Region of southern Chile. The aim of the present contribution is to describe a new specimen of gondwanatherian mammaliaforms from beds belonging to the Maastrichtian Chorrillo Formation, cropping out 30 km SW of El Calafate, Santa Cruz Province, Argentina. It is represented by a single molariform referable to the species Magallanodon baikashkenke with which it shares a unique combination of characters. Analysis of the unique combination of characters exhibited by Magallanodon shed doubts on the monophyly of Ferugliotheriidae and suggest that South American taxa may be closely related to each other. The wide geographical distribution and occurrence of gondwanatherians on geological units of diverse origins suggest that they were capable of facing disparate environmental conditions.