environments by mixing high browsing with low browsing and grazing. A site in northern Chile preserved the remains of five subadults associated together, which suggests Macrauchenia may have lived in large herds or family groups. When Macrauchenia first arose, it could have been preyed upon by the largest of native South American mammal predators, the sabertoothed sparassodont Thylacosmilus. The largest phorusrhacid birds may also have been able to prey on juveniles. After the GABI, the primary predator on adults would have been the very large sabertoothed cat Smilodon populator and giant short-faced bears. Dire wolves and jaguars may also have hunted Macrauchenia, particularly juveniles. It is presumed that Macrauchenia dealt with its predators primarily by outrunning them, or, failing that, kicking them with its long, powerful legs. The large size of adults would have limited their vulnerability to most predators. Its potential ability to twist and turn at high speed could have enabled it to evade pursuers; both Thylacosmilus and S. populator were ambush hunters likely unable to run down prey over distance if the prey evaded the first attack. Distribution Fossils of Macrauchenia'' have been found in: Miocene Epecuén Formation, Argentina Pliocene Argentina Pleistocene Arroyo Seco and Luján Formations, Argentina Ulloma, Charana, Umala, Tarija and Ñuapua Formations, Bolivia Touro Passo Formation, Brazil Cueva del Milodón, Chile Paraguay San Sebastián Formation, Peru Sopas and Dolores Formations, Uruguay Taima-Taima, Venezuela References Further reading Barry Cox, Colin Harrison, R.J.G. Savage, and Brian Gardiner. (1999): The Simon & Schuster Encyclopedia of Dinosaurs and Prehistoric Creatures: A Visual Who's Who of Prehistoric Life. Simon & Schuster. Jayne Parsons. (2001): Dinosaur Encyclopedia. DK. External links Megafauna page Macraucheniids Messinian first appearances Holocene extinctions Miocene mammals of South America Pliocene mammals of South America Pleistocene mammals of South America Lujanian Ensenadan Uquian Chapadmalalan Montehermosan Huayquerian Neogene Argentina Cerro Azul Formation Pleistocene Argentina Pleistocene Bolivia Pleistocene Brazil Pleistocene Chile Pleistocene Paraguay Pleistocene Peru Pleistocene Uruguay Pleistocene Venezuela Fossils of Argentina Fossils of Bolivia Fossils of Brazil Fossils of Chile Fossils of Paraguay Fossils of Peru Fossils of Uruguay Fossils of Venezuela Fossil taxa described in 1838 Taxa named by Richard Owen Prehistoric placental genera