En la Antártida, paleontólogos argentinos descubrieron fósiles de un pingüino de unos 2 metros de altura, el más grande encontrado hasta el momento, con una antigüedad de 34 millones de años. La paleontóloga Carolina Acosta, investigadora del Museo de La Plata, explicó que "los cálculos realizados indican que se trata del pingüino más grande que se conoce hasta el momento, en cuanto a altura y masa corporal". En la actualidad,  la especie de mayor tamaño es el Pingüino emperador, que alcanza los 1,20 metros. El descubrimiento, realizado por Marcelo Reguero, director de la campaña paleontológica del Instituto Antártico Argentino, fue posible debido al hallazgo, por primera vez en la Antártida, de un esqueleto articulado del animal, lo que permitió obtener mayor información sobre su anatomía y cómo se movía. Los restos permitieron a Acosta reconstruir parte de la musculatura del pingüino gigante, que "debía emplear más fuerza para impulsarse en el agua y tenía una musculatura más desarrollada". La reconstrucción no proporcionó elementos para definir a qué género perteneció el pingüino gigante, aunque la especialista adelantó que el objetivo de la campaña antártica del próximo verano será "buscar nuevos esqueletos" para continuar con la investigación.
Fuente: colectivosalas.blogspot.com.ar

Fernando E. Novas, Martin Kundrat, Federico L. Agnolín,  Martín D. Ezcurra, Per Erik Ahlberg, Marcelo P. Isasi,  Alberto Arriagada, y Pablo Chafrat

Here, we expand the meager record of Late Cretaceous South American pterosaurs with the description of a partial rostrum belonging to a large azhdarchid pterodactyloid. The specimen was collected close to the Bajo de Arriagada locality, corresponding to the uppermost Cretaceous Allen Formation of Argentina, around 80 km northwest of the well-sampled Bajo de Santa Rosa locality (Martinelli and Forasiepi, 2004). The Azhdarchidae were the most abundant pterosaurs during latest Cretaceous times (Company et al., 1999; Butler et al., 2009). This clade comprises several species of long-necked pterosaurs ranging from 2.5 to 10 m in wing span, thus including the largest known flying vertebrates, such as the gigantic Quetzalcoatlus and Hatzegopteryx (Kellner and Langston, 1996; Buffetaut et al., 2002; Witton and Naish, 2008; Witton and Habib, 2010). Azhdarchid remains have been documented from almost all continental landmasses, includ-ing Europe, North America, Africa, Asia, and probably Oceania (Bennett and Long, 1991; Company et al., 1999; Averianov et al., 2005; Barrett et al., 2008; Kear et al., 2010; ˝Osi et al., 2011). In South America, probable azhdarchid remains consist of a fragmentary postcranial skeleton from the Aptian of Brazil (Martill and Frey, 1998, 1999) and partial long bones from the Turonian–Coniacian of Argentina (Kellner et al., 2006; Codorniú and Gasparini, 2007). However, recent reassessments of this material suggested that the Brazilian specimen is more closely related to tapejarids than to azhdarchids and that the Argentinean records are dubious (Kellner, 2004; Kellner et al., 2006; Unwin and Martill, 2007). As a result, the specimen reported here represents the first unambiguous evidence of an azhdarchid pterosaur from South America. This specimen represents a new genus and species, Aerotitan sudamericanus, which is diagnosed based on a unique combination of characters, including one autapomorphy, and represents one of the largest known South American pterosaurs. The fossil here described resulted from a joint Argentine-Swedish paleontological expedition to Patagonia.

Novas, F. E., Kundrat, M., Agnolín, F. L., Ezcurra, M. D., Ahlberg, P. E., Isasi, M. P., Arriagada, A. y Chafrat, P. 2012. A New Large Pterosaur From The Late Cretaceous Of Patagonia. Journal of Vertebrate Paleontology 32(6):1447–1452


P.J. Pazos, D. G. Lazo, M. A. Tunik, C. A. Marsicano, D.E. Fernández, M. B. Aguierre-Urreta

The study of the uppermost section of the Early Cretaceous Agrio Formation in northern Patagonia (Neuquén Basin) where dinosaur tracks assigned to cf. Therangospodus pandemicus are exposed (tracksites I and II) evidence mixed marginal marine siliciclastic-carbonate deposits. The succession was divided in two intervals. A lower one containing theropod tracks, recorded on top of subtidal oolithic limestones with tiny wave ripples suggesting shoreline fluctuations and subaerial exposure. Tidal influence is recognised by fining upward and prograding cycles starting with subtidal carbonates and ending with fine-grained siliciclastic deposits at the top, or rarely laminites. Dolomitization affects subtidal deposits generated in an alkaline media stressful for tracemakers. Intertidal facies include abundant heterolithic deposits, coquinas composed of gastropods encrusted by multilayered bryozoans and muddy levels with incipient mud cracking. Invertebrate ichnofossils recognized from tidally dominated deposits include Arenicolites, Kouphichnium, and Rhizocorallium. The upper interval is a transgressive–regressive cycle that starts with dark shales, deficiently oxygenated, and covered by prograding sandstones and finally sand flat deposits. This interval contains Gyrochorte, Hillichnus, and Ophiomorpha documented in wave-influenced sandstones. Dinosaur tracks as well as Hillichnus, attributed to tellinoid bivalves, and Kouphichnium assigned to xiphosurans, imply the activity of producers rarely recorded previously as body fossils in marginal marine deposits of southern South America. Previous paleogeographic schemes are questioned by our analysis, which shows evidence of extremely shallow and tide-controlled sedimentation, sometimes with subaerial exposure, with high cyclicity related to a marginal marine depositional setting and lack of significant erosion by the overlying unit, as traditionally was suggested.

P.J. Pazos, D. G. Lazo, M. A. Tunik, C. A. Marsicano, D.E. Fernández, M. B. Aguirre-Urreta 2012.Paleoenvironmental framework of dinosaur tracksites and other ichnofossils in Early Cretaceous mixed siliciclastic-carbonate deposits in the Neuquén Basin, northern Patagonia (Argentina).Gondwana Research 22: 1125-1140.