After so many decades of North American and Euro-Asian dinosaur discoveries, the relatively unexplored (until recent times)South America has turned into the source of some of the most unusual dinosaur fauna. Argentina in particular owns some of the richest dinosaur deposits in the whole world.
Amargasaurus (saurian from La Amarga Formation in Argentina), a moderately sized dicraeosaurid closely related to Dicraeosaurus (and part of the diplodocid family) is surely the strangest-looking sauropod ever found. Discovered and described by Jos Bonaparte and his team, this animal challenged everything that was assumed about this long-necked dinosaur family. The incredibly elongated cervical vertebrae are the issue of much debate. Some workers have hypothesised a hump (a kind of camel dinosaur), others a sail (to regulate temperature) and most recently (Greg Paul and others) that the elongated spines were covered by a horny sheath, like a gigantic porcupine. No matter what interpretation, it must have been an awesome display. I have chosen for this painting the horny sheath theory (for another version see the South American Dinosauria painting). I depict two bull males displaying to each other, while a small noasaurid (South American equivalent of, but not directly related to Velociraptor) and some indeterminate hypsilophodontids are rather indifferent passers-by.