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Ericson P.G.P.,Swedish Museum of Natural History | Olson S.L.,Smithsonian Institution | Irestedt M.,Swedish Museum of Natural History | Alvarenga H.,Museu de Historia Natural de Taubate | Fjeldsa J.,Copenhagen University
Journal of Ornithology | Year: 2010

The tapaculos (Rhinocryptidae) are tracheophone, suboscine birds restricted to South and Central America. Most tapaculos share a number of internal and external characteristics that have been used to define the family taxonomically. The genera Melanopareia and Psiloramphus do not fully fit this pattern and have caused considerable dispute among taxonomists since they were first described. In this paper we delimit the systematic boundaries of the tapaculos and assess their generic relationships by analysis of molecular sequence data. The results show that whereas Psiloramphus is nested well within the Rhinocryptidae, Melanopareia falls far outside that clade. A new family is erected for Melanopareia. © 2009 Dt. Ornithologen-Gesellschaft e.V. Source


Mayr G.,Senckenberg Institute | Alvarenga H.,Museu de Historia Natural de Taubate | Mourer-Chauvire C.,University Claude Bernard Lyon 1
Naturwissenschaften | Year: 2011

We describe the earliest fossils of the enigmatic avian taxon Opisthocomiformes (hoatzins) from the Oligo-Miocene (22-24 mya) of Brazil. The bones, a humerus, scapula and coracoid, closely resemble those of the extant hoatzin, Opisthocomus hoazin. The very similar osteology of the pectoral girdle in the new Brazilian fossil compared to the extant O. hoazin, in which it reflects peculiar feeding adaptations, may indicate that hoatzins had already evolved their highly specialized feeding behavior by the mid-Cenozoic. We further show that Namibiavis senutae from the early Miocene of Namibia is another, previously misclassified representative of Opisthocomiformes, which documents that the extant Neotropic distribution of hoatzins is relictual. Because of the weak flight capabilities of hoatzins, their occurrence on both sides of the South Atlantic is of particular biogeographic interest. We detail that this distribution pattern is best explained by dispersal from Africa to South America, and that Opisthocomiformes provide the first example of transatlantic rafting among birds. © 2011 Springer-Verlag. Source


Mayr G.,Senckenberg Institute | Alvarenga H.,Museu de Historia Natural de Taubate | Clarke J.A.,University of Texas at Austin
Acta Palaeontologica Polonica | Year: 2011

We describe a new avian taxon, Itaboravis elaphrocnemoides, gen. et sp. nov., from the late Paleocene fissure fillings of So Jos de Itabora in Brazil. The species is represented by a coracoid and two humeri, which most closely resemble the corresponding elements of the taxon Elaphrocnemus, a proposed stem group representative of the Cariamae from the late Eocene and Oligocne of the Quercy fissure fillings in France. I. elaphrocnemoides is only the second species of small landbird known from the Paleocene of the Southern Hemisphere. It is tentatively classified in the Cariamae, but we also note morphological similarities of the humerus to that of the palaeognathous Tinamidae. We further describe a carpometacarpus, which exhibits a peculiar morphology not found in any other avian taxon. This bone also shares some features with tinamous and is of a size corresponding to that of I. elaphrocnemoides, but cannot be referred to this taxon with confidence. We finally report four morphologically different distal tibiotarsi, one of which may belong to Eutreptodactylus itaboraiensis, the only other small bird described from Itabora. Source


Alvarenga H.,Museu de Historia Natural de Taubate | Jones W.,Museo Nacional de Historia Natural y Antro pologia | Rinderknecht A.,Museo Nacional de Historia Natural y Antro pologia
Neues Jahrbuch fur Geologie und Palaontologie - Abhandlungen | Year: 2010

We report the youngest record of a phorusrhacid bird based on a distal portion of a right tarsometatarsus. This fossil comes from late Pleistocene sediments of Uruguay. The age determination was based on lithological features, biostratigraphical studies and absolute dating. The evidence indicates that these groundbirds co-occurred with the typical Pleistocene South American megafaunal mammals. The so far youngest fossils of phorusrhacids stem from the Pliocene or lower Pleistocene of South and North America. © 2010 Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany. Source


Bershaw J.,University of Rochester | Garzione C.N.,University of Rochester | Higgins P.,University of Rochester | MacFadden B.J.,University of Florida | And 3 more authors.
Earth and Planetary Science Letters | Year: 2010

Paleoelevation constraints from fossil leaf physiognomy and stable isotopes of sedimentary carbonate suggest that significant surface uplift of the northern Andean plateau, on the order of 2.5 ± 1 km, occurred between ∼ 10.3 and 6.4 Ma. Independent spatial and temporal constraints on paleoelevation and paleoclimate of both the northern and southern plateau are important for understanding the distribution of rapid surface uplift and its relation to climate evolution across the plateau. This study focuses on teeth from modern and extinct mammal taxa (including notoungulates, pyrotheres, and litopterns) spanning ∼ 29 Ma to present, collected from the Altiplano and Eastern Cordillera of Bolivia (16.2°S to 21.4°S), and lowland Brazil. Tooth enamel of large, water-dependent mammals preserves a record of surface water isotopes and the type of plants that animals ingested while their teeth were mineralizing. Previous studies have shown that the δ18O of modern precipitation and surface waters decrease systematically with increasing elevations across the central Andes. Our results from high elevation sites between 3600 and 4100 m show substantially more positive δ18O values for late Oligocene tooth samples compared to < 10 Ma tooth δ18O values. Late Oligocene teeth collected from low elevation sites in southeast Brazil show δ18O values similar (within 2‰) to contemporaneous teeth collected at high elevation in the Eastern Cordillera. This affirms that the Andean plateau was at a very low elevation during the late Oligocene. Late Oligocene teeth from the northern Eastern Cordillera also yield consistent δ13C values of about - 9‰, indicating that the environment was semi-arid at that time. Latitudinal gradients in δ18O values of late Miocene to Pliocene fossil teeth are similar to modern values for large mammals, suggesting that by ∼ 8 Ma in the northern Altiplano and by ∼ 3.6 Ma in the southern Altiplano, both regions had reached high elevation and established a latitudinal rainfall gradient similar to modern. © 2009 Elsevier B.V. Source

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