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Pelecanus paranensis sp. nov., a new pelican (Aves, Pelecanidae) from the marine Upper Miocene Paraná Formation, which crops out in the Province of Entre Ríos, Argentina, is described. This record constitutes the first report of a fossil pelican from Argentina and the southernmost from South America. The holotypical specimen consists of a very large and nearly complete pelvis, which is characterized by having the cristae iliacae dorsales continuous throughout its entire length and a large foramen acetabuli. The U-shaped morphology of the postacetabular section of the pelvis of the new species as well as the wide incisura sutura iliosynsacralis, allow to infer its phylogenetic position within the New World pelican species clade, showing a close relationship with the clade (P. occidentalis + P. thagus). A probable transAtlantic dispersal route for the ancestor of the New World pelicans is thus inferred. The inland Paranaense Sea, which flooded the South American Chaco-Paraná basin during the mid-Neogene, is proposed as a south-north pathway for ancestral forms of the clade (P. occidentalis + P. thagus). These regressive marine paleoenvironments of the Late Miocene may have acted as the evolutionary driver for the transition of pelican species from brackish or freshwater habitats to those inhabiting strictly marine coastlines. [ABSTRACT FROM AUTHOR]

Author(s): Julia A. Clarke (corresponding author) [1, 2]; Claudia P. Tambussi [3]; Jorge I. Noriega [4]; Gregory M. Erickson [5, 6, 7]; Richard A. Ketcham [8] Long-standing controversy [1, 2, [...]

A joint paleontological expedition of the Museo Argentino de Ciencias Naturales and the State University of New York at Stony Brook have recovered an Early Miocene Passeriform fossil from the Pinturas Formation in Santa Cruz Province, Argentina. The fossil is a nearly complete distal end of a right humerus. The brachial fossa, ventral supracondylar tubercle, distal condyles and other parts of the fossil are described.

Author(s): Julia A. Clarke; Claudia P. Tambussi; Jorge I. Noriega; Gregory M. Erickson; Richard A. Ketcham Nature 433, 305-308 (2005) We wish to correct an oversight noted [1] in one [...]

Seriemas (Cariamidae) include two extant species, Cariama cristata and Chunga burmeisteri, which live in semi-open plains of South America and have a poorly documented evolutionary history. One of the earliest fossil representatives of Cariamidae is the recently described Noriegavis santacrucensis from the early Miocene Santa Cruz Formation (Argentina). So far, however, this species was only known from a cranium and tentatively referred distal tibiotarsi, and its phylogenetic assignment has been questioned. Here we describe a well-preserved partial skeleton from the Santa Cruz Formation, which substantiates the classification of Noriegavis in Cariamidae. Plesiomorphic features show N. santacrucensis to be outside crown group Cariamidae, but the species is nevertheless very similar to its modern relatives and documents that the osteology of seriemas underwent only few changes during the past 16 million years. [ABSTRACT FROM AUTHOR]

The Late Miocene vertebrate fauna from the Entre Ríos Province, Argentina, comes from two units: the marine Paraná Formation and the Lower Member of Ituzaingó Formation (LMIF). This latter includes a lower conglomerate set, with fine quartz gravel, and clay and chalcedony clasts, and fossil remains, traditionally known as ‘Mesopotamiense’ or ‘Conglomerado osífero’. We present new fossil vertebrate remains from the LMIF at the Puerto Víboras locality (Hernandarias, Entre Ríos Province) including Leptodactylus sp. (Amphibia, Anura), Crocodylia indet. Caimaninae indet. and Paranasuchus gasparinae (Alligatoridae), Chelidae indet. (Testudines, Pleurodira), Chelonoidis sp. (Testudines, Cryptodira), Plohophorus paranensis (Cingulata, Glyptodontidae), and Macraucheniinae indet. (Macraucheniidae, Litopterna). The record of Leptodactylus sp. represents the oldest record of the genus and the first amphibian record for the Neogene of the Entre Ríos Province. The material described herein and assigned to Chelonoidis sp. allows to confirm for the first time the presence of a testudinid in the Late Miocene of the Entre Ríos Province. [ABSTRACT FROM AUTHOR]