Dinosaurs (Reptilia, Archosauria) at Museo de La Plata, Argentina: annotated catalogue of the type material and Antarctic specimens

A commented-illustrated catalogue of non-avian dinosaurs housed at Museo de La Plata, Argentina is presented. This represents the first commented catalogue of the La Plata Museum dinosaurs to be published. This includes the type material as well as Antarctic specimens. The arrangement of the material was made in a phylogenetic fashion, including systematic rank, type material, referred specimens, geographic and stratigraphic location, and comments/remarks, when necessary. A total of 13 type specimens of non-avian dinosaurs are housed at the collection of Museo de La Plata, including eight sauropods, one theropod, one ornithischian, and three ichnotaxa. There are four Antarctic specimens, one of which is a holotype, whereas other corresponds to the first sauropod dinosaur registered for that continent.Fil: Otero, Alejandro. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reguero, Marcelo Alfredo. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Dinosaurs (Reptilia, Archosauria) at Museo de La Plata, Argentina: annotated catalogue of the type material and Antarctic specimens

A commented-illustrated catalogue of non-avian dinosaurs housed at Museo de La Plata, Argentina is presented. This represents the first commented catalogue of the La Plata Museum dinosaurs to be published. This includes the type material as well as Antarctic specimens. The arrangement of the material was made in a phylogenetic fashion, including systematic rank, type material, referred specimens, geographic and stratigraphic location, and comments/remarks, when necessary. A total of 13 type specimens of non-avian dinosaurs are housed at the collection of Museo de La Plata, including eight sauropods, one theropod, one ornithischian, and three ichnotaxa. There are four Antarctic specimens, one of which is a holotype, whereas other corresponds to the first sauropod dinosaur registered for that continent.Facultad de Ciencias Naturales y Muse

Ancient proteins resolve the evolutionary history of Darwin’s South American ungulates

No large group of recently extinct placental mammals remains as evolutionarily cryptic as the approximately 280 genera grouped as 'South American native ungulates'. To Charles Darwin, who first collected their remains, they included perhaps the 'strangest animal[s] ever discovered'. Today, much like 180 years ago, it is no clearer whether they had one origin or several, arose before or after the Cretaceous/Palaeogene transition 66.2 million years ago, or are more likely to belong with the elephants and sirenians of superorder Afrotheria than with the euungulates (cattle, horses, and allies) of superorder Laurasiatheria. Morphology-based analyses have proved unconvincing because convergences are pervasive among unrelated ungulate-like placentals. Approaches using ancient DNA have also been unsuccessful, probably because of rapid DNA degradation in semitropical and temperate deposits. Here we apply proteomic analysis to screen bone samples of the Late Quaternary South American native ungulate taxa Toxodon (Notoungulata) and Macrauchenia (Litopterna) for phylogenetically informative protein sequences. For each ungulate, we obtain approximately 90% direct sequence coverage of type I collagen α1- and α2-chains, representing approximately 900 of 1,140 amino-acid residues for each subunit. A phylogeny is estimated from an alignment of these fossil sequences with collagen (I) gene transcripts from available mammalian genomes or mass spectrometrically derived sequence data obtained for this study. The resulting consensus tree agrees well with recent higher-level mammalian phylogenies. Toxodon and Macrauchenia form a monophyletic group whose sister taxon is not Afrotheria or any of its constituent clades as recently claimed, but instead crown Perissodactyla (horses, tapirs, and rhinoceroses). These results are consistent with the origin of at least some South American native ungulates from 'condylarths', a paraphyletic assembly of archaic placentals. With ongoing improvements in instrumentation and analytical procedures, proteomics may produce a revolution in systematics such as that achieved by genomics, but with the possibility of reaching much further back in time.La lista completa de autores puede consultarse en el documento o en la página web de la revista.Facultad de Ciencias Naturales y Muse

Antarctic Paleontological Heritage: Late Cretaceous Paleogene vertebrates from Seymour (Marambio) Island, Antarctic Peninsula

Antarctica has significant environmental, scientific, historic, and intrinsic values, all of which are worth protecting into the future. This continent has a discrete number of places of scientific interest that exhibit great potential as natural heritage sites; its geodiversity is of fundamental importance to scientific values of the continent, and the pursuit of geological and paleontological knowledge has had a strong influence on its historical values. Seymour Island was once called the ‘Rosetta Stone’ of Southern Hemisphere paleobiology, because this small island provides the most complete and richly fossiliferous Late Cretaceous–Paleogene sequence in Antarctica. In particular, fossil vertebrates form part of the evidence used in reconstructing the history of life on Antarctica. Paleontological heritage is considered a subset of geo-heritage that embodies both natural and historical components which has received only indirect recognition. Seymour Island is an outstanding paleontological area with high heritage value of its Late Cretaceous/Paleogene vertebrates and should be considered for geo-conservation and protection. This paper reviews vertebrate fossil occurrences and outcrops on Seymour Island and discusses some threats to these fossil sites

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

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, Prohegetotherium malalhuense sp. nov., and the pachyrukhine Propachyrucos cf. P. simpsoni. The presence of Prosotherium cannot be totally discarded as lower molariforms are rather similar between both pachyrukhine genera. The new species Prohegetotherium malalhuense sp. nov. differs from all previously described hegetotheriines by lingually projecting, sharp parastyle and marked parastyle groove on ectoloph of M2-3; talonid of m1-m2 posterolabially projected; talonid of m3 with marked posterolabial groove; and smaller size. Its phylogenetic affinities are not well resolved; Prohegetotherium results paraphyletic, with P. sculptum as sister taxon of the remaining hegetotheres, and the new taxon more 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 seem to support a significant faunal provinciality in South America during the late Oligocene.Facultad de Ciencias Naturales y Muse

First fossil frog from Antarctica: Implications for Eocene high latitude climate conditions and Gondwanan cosmopolitanism of Australobatrachia

Cenozoic ectothermic continental tetrapods (amphibians and reptiles) have not been documented previously from Antarctica, in contrast to all other continents. Here we report a fossil ilium and an ornamented skull bone that can be attributed to the Recent, South American, anuran family Calyptocephalellidae or helmeted frogs, representing the first modern amphibian found in Antarctica. The two bone fragments were recovered in Eocene, approximately 40 million years old, sediments on Seymour Island, Antarctic Peninsula. The record of hyperossified calyptocephalellid frogs outside South America supports Gondwanan cosmopolitanism of the anuran clade Australobatrachia. Our results demonstrate that Eocene freshwater ecosystems in Antarctica provided habitats favourable for ectothermic vertebrates (with mean annual precipitation ≥900 mm, coldest month mean temperature ≥3.75 °C, and warmest month mean temperature ≥13.79 °C), at a time when there were at least ephemeral ice sheets existing on the highlands within the interior of the continent.Fil: Mörs, Thomas. Stockholms Universitet; SueciaFil: Reguero, Marcelo Alfredo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Vasilyan, Davit. University of Fribourg; Suiz

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

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, Prohegetotherium malalhuense sp. nov., and the pachyrukhine Propachyrucos cf. P. simpsoni. The presence of Prosotherium cannot be totally discarded as lower molariforms are rather similar between both pachyrukhine genera. The new species Prohegetotherium malalhuense sp. nov. differs from all previously described hegetotheriines by lingually projecting, sharp parastyle and marked parastyle groove on ectoloph of M2?3; talonid of m1?m2 posterolabially projected; talonid of m3 with marked posterolabial groove; and smaller size. Its phylogenetic affinities are not well resolved; Prohegetotherium results paraphyletic, with P. sculptum as sister taxon of the remaining hegetotheres, and the new taxon more 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 seem to support a significant faunal provinciality in South America during the late Oligocene.Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Reguero, Marcelo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico de Paleontología de Vertebrados; Argentin

El problema de las relaciones sistemáticas y filogenéticas de los Typotheria y Hegetotheria (Mammalia, + Notoungulata) : análisis de los taxones de Patagonia de la edad-mamífero Deseadense (Oligoceno)

Fil: Reguero, Marcelo A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

First articulated skeleton of Palaeeudyptes gunnari from the late eocene of isla marambio (Seymour Island), Antarctica

The first articulated skeleton of a penguin from the late Eocene of Antarctica is described. MLP 96-I-6-13 comes from the upper Submeseta Allomember (La Meseta Formation) of Seymour Island (locality DPV 10/84). The significance of this finding in the context of the Anthropornis nordenskjoeldi biozone is discussed. An osteologic description of the recovered elements and a brief discussion of its systematic determination are provided. MLP 96-I-6-13 is the first articulated skeleton with sure specific assignment to Palaeeudyptes gunnari (Wiman 1905), a species previously known only through isolated tarsometatarsi and included in the groups of Wiman.Fil: Acosta Hospitaleche, Carolina Ileana Alicia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Reguero, Marcelo Alfredo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

First articulated skeleton of <i>Palaeeudyptes gunnari</i> from the late Eocene of Isla Marambio (Seymour Island), Antarctica

The first articulated skeleton of a penguin from the late Eocene of Antarctica is described. MLP 96-I-6-13 comes from the upper Submeseta Allomember (La Meseta Formation) of Isla Marambio (locality DPV 10/84). The significance of this finding in the context of the Anthropornis nordenskjoeldi biozone is discussed. An osteologic description of the recovered elements and a brief discussion of its systematic determination are provided. MLP 96-I-6-13 is the first articulated skeleton with sure specific assignment to Palaeeudyptes gunnari (Wiman, 1905), a species previously known only through isolated tarsometatarsi and included in the groups of Wiman.Facultad de Ciencias Naturales y Muse