The Chacoan peccary or tagua (Catagonus wagneri or Parachoerus wagneri) is the last extant species of the genus Catagonus; it is a peccary found in the Gran Chaco of Paraguay, Bolivia, and Argentina. Approximately 3,000 remain in the world. The Chacoan peccary has the unusual distinction of having been first described in 1930 based on fossils and was originally thought to be an extinct species. In 1971, the animal was discovered to still be alive in the Chaco region, in the Argentine province of Salta. The species was well known to the native people, but it took a while for Western scientists to acknowledge its existence. It is known locally as the tagua. Taxonomy The Chacoan peccary is notable in that it is not the type species of its genus, Catagonus, despite being the only living representative. Instead, the type is the extinct Catagonus metropolitanus. Such a case is an example of a Lazarus taxon, and shares this trait with another South American native, the bush dog. The Chacoan peccary was first described by scientists in 1972. A 2017 study on the phylogenetic systematics of Tayassuidae species suggests that Catagonus should only contain C. metropolitanus. The extinct narrow-headed peccary (C. stenocephalus) should be moved into Brasiliochoerus, while the Chacoan peccary, Catagonus bonaerensis and Catagonus carlesi should be placed in Parachoerus. If this is accepted, then Catagonus becomes an extinct genus once more. Habitat The Chacoan peccary is confined to hot, dry areas. Dominated by low-lying succulents and thorny bushes, the Gran Chaco is about 140,000 km2. A few scattered giant trees are found, but the majority of the vegetation is thorny scrub vegetation. The Chacoan peccary has developed adaptations such as well-developed sinuses to combat dry, dusty conditions. Their feet are also small, which allows maneuverability among spiny plants. Physical characteristics The largest of the three generally accepted species of peccaries, the Chacoan peccary has many pig-like features. It is an ungulate with a well-formed rostrum with a tough leathery snout. The bristle-like hair is generally brown to almost gray. A dark stripe runs across the back, and white fur is on the shoulders. Chacoan peccaries differ from other peccary species by having longer ears, snouts, and tails. It has white hairs around the mouth, unlike other peccaries. Catagonus wagneri also has a third hind toe, but other peccaries only have two. The hypsodont teeth follow this dental formula: 2/3,