Aberrant Fossil Ungulates of South America

An exceptional fossil skull from South America and the origins of the archosauriform radiation

Birds, dinosaurs, crocodilians, pterosaurs and their close relatives form the highly diverse clade Archosauriformes. Archosauriforms have a deep evolutionary history, originating in the late Permian, prior to the end-Permian mass extinction, and radiating in the Triassic to dominate Mesozoic ecosystems. However, the origins of this clade and its extraordinarily successful body plan remain obscu...

Archaeology of South America

19th century South America

This basic socio-cultural framework, with all its inherent ambivalences and contradictions, emerged during the colonial era and exercised a deep and lasting impact on the political, economic and social structure of the new South American nations. Only after many decades was the impact blurred by the action of other external influences, change occurring from within, and a growing sense of nation...

Giant Fossil Soft-Shelled Turtles of North America

Axestemys byssina—a large, potentially paedomorphic soft-shelled turtle (Trionychidae)—and a number of other of giant trionychids have been described, but no rigorous analysis has been undertaken to investigate their relationships. Because these trionychids are so unusual and occupy a broad Cretaceous-Eocene temporal range (70-46 myr), their study provides new insights into broad patterns of tr...

Description of the Earliest Fossil Penguin from South America and First Paleogene Vertebrate Locality of Tierra Del Fuego, Argentina

We report the discovery of the first vertebrate from the Paleogene of Tierra del Fuego (Isla Grande), Argentina, in southernmost South America. The specimen consists of parts of an associated pelvic girdle and limb that are identified as belonging to the penguin stem clade (Aves: Pansphenisciformes). The specimen, from an exposure of the Leticia Formation (late middle Eocene), is the earliest k...