Question: When did the continent home to the river of which Tebicuary River is a tributary take the form it has today?

full_context: Document 1: Juruá River: The Juruá River (Portuguese "Rio Juruá"; Spanish "Río Yurúa") is a southern affluent river of the Amazon River west of the Purus River, sharing with this the bottom of the immense inland Amazon depression, and having all the characteristics of the Purus as regards curvature, sluggishness and general features of the low, half-flooded forest country it traverses.
Document 2: Indigenous peoples in Canada: The first inhabitants of North America arrived in Canada at least 15,000 years ago, though increasing evidence suggests an even earlier arrival. It is believed the inhabitants entered the Americas pursuing Pleistocene mammals such as the giant beaver, steppe wisent, musk ox, mastodons, woolly mammoths and ancient reindeer (early caribou). One route hypothesized is that people walked south by way of an ice - free corridor on the east side of the Rocky Mountains, and then fanned out across North America before continuing on to South America. The other conjectured route is that they migrated, either on foot or using primitive boats, down the Pacific Coast to the tip of South America, and then crossed the Rockies and Andes. Evidence of the latter has been covered by a sea level rise of hundreds of metres following the last ice age.
Document 3: Paraguay: Paraguay (; ; , ), officially the Republic of Paraguay (; ), is a country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Although it is one of only two landlocked countries in South America (the other is Bolivia), the country has coasts, beaches and ports on the Paraguay and Paraná rivers that give exit to the Atlantic Ocean through the . Due to its central location in South America, it is sometimes referred to as "Corazón de Sudamérica" ("Heart of South America").
Document 4: Llama: Llamas appear to have originated from the central plains of North America about 40 million years ago. They migrated to South America about three million years ago during the Great American Interchange. By the end of the last ice age (10,000 -- 12,000 years ago), camelids were extinct in North America. As of 2007, there were over seven million llamas and alpacas in South America, and due to importation from South America in the late 20th century, there are now over 158,000 llamas and 100,000 alpacas in the United States and Canada.
Document 5: Tebicuary River: The Tebicuary River (Spanish: Río Tebicuary), a tributary of Paraguay River is a river in Paraguay. Located in the southwestern part of that country, it flows eastwards discharging to Paraguay River about 45 km south of Formosa and 30 km north of Pilar.
Document 6: History of South America: In the last million years since the Late Miocene, South America became connected with the continent of North America via the Panama Block that closed the marine Bolivar Trough, leading to the Great American Interchange, the interchange of biota from both continents. The first species discovered to have made the northward migration was Pliometanastes, a fossil ground sloth species, roughly the size of a modern black bear. Several migrations to the Southern Hemisphere were undertaken by tougher, North American mammal carnivores; fewer species migrated in the opposite direction from south to north. The result of the intrusion of North American fauna was that hundreds of South American species became extinct in a relatively short time and that about 60% of present - day South American mammals have evolved from North American species. However, some species were able to adapt and spread into North America. Apart from Pliometanastes, during the Irvingtonian stage of the mammal land stages, around 1.9 Ma, species as Pampatherium, a giant armadillo, ground sloth Megatherium, giant anteater Myrmecophaga, a Neogene capybara (Hydrochoerus), Meizonyx, opossum Didelphis, and Mixotoxodon followed the route north. The terror bird Titanis was the only discovered South American carnivore species who made the journey into North America.
Document 7: Guaíra, Paraná: Guaíra is a municipality in the state of Paraná in the Southern Region of Brazil. The population is 32,591 (2015 est.) in an area of 560 km². The elevation is 517 m. This place name comes from the Tupi language and means "place difficult to access". The city is served by Guaíra Airport.
Document 8: Paraguay River: The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in the Brazilian state of Mato Grosso to its confluence with the Paraná River north of Corrientes and Resistencia.
Document 9: San Ignacio de Loyola International Bridge: The San Ignacio de Loyola International Bridge (Spanish: Puente Internacional San Ignacio de Loyola) is a road bridge that crosses the border between Argentina and Paraguay over the Pilcomayo River, from the Argentine city of Clorinda, to José Falcón, near Asunción, Paraguay's capital.
Document 10: Indigenous peoples of the Americas: According to the prevailing theories of the settlement of the Americas, migrations of humans from Asia (in particular North Asia) to the Americas took place via Beringia, a land bridge which connected the two continents across what is now the Bering Strait. The majority of experts agree that the earliest pre-modern human migration via Beringia took place at least 13,500 years ago, with disputed evidence that people had migrated into the Americas much earlier, up to 40,000 years ago. These early Paleo-Indians spread throughout the Americas, diversifying into many hundreds of culturally distinct nations and tribes. According to the oral histories of many of the indigenous peoples of the Americas, they have been living there since their genesis, described by a wide range of creation myths.
Document 11: São Lourenço River (Mato Grosso): The São Lourenço River is a tributary of the Paraguay River within the Pantanal, an alluvial plain that spans portions of Brazil, Bolivia and Paraguay.
Document 12: Quiquibey River: The Quiquibey River is a river in the Pilón Lajas Biosphere Reserve and Communal Lands in the north of Bolivia. The Quiquibey River joins the Beni River south of Rurrenabaque (upstream and south of Beni's tributary the Tuichi River). The river is the border between the departments of Beni and La Paz.
Document 13: Guaporé River: Guaporé River (Portuguese: Rio Guaporé) is a river in western Brazil and northeastern Bolivia. Its Bolivian name is Río Iténez. It is 1,530 km (950 mi) long; 970 km (600 mi) of the river forms the border between Brazil and Bolivia.
Document 14: Bermejo River: The Bermejo River (Spanish, Río Bermejo) is a river in South America that flows from Bolivia to the Paraguay River in Argentina. The river is generally called Bermejo in spite of its different names along its way, but it also has its own Native American names; in Wichí it is called Teuco, and in Guaraní it is called Ypitá. In the plains of Argentina's Gran Chaco the Bermejo forms wetlands and splits into two branches. The southern branch is the bed of the old Bermejo River, now an intermittent stream called Río Bermejito. The northern branch is now the main stem of the Bermejo and is called the Teuco River ("Río Teuco"), Bermejo Nuevo, or simply the Bermejo River. The two branches rejoin at , near Villa Río Bermejito, forming the Lower Bermejo River.
Document 15: Isthmus of Panama: A significant body of water (referred to as the Central American Seaway) once separated the continents of North and South America, allowing the waters of the Pacific and Atlantic Oceans to mix freely. Beneath the surface, two plates of the Earth's crust were slowly colliding, forcing the Cocos Plate to slide under the Caribbean Plate. The pressure and heat caused by this collision led to the formation of underwater volcanoes, some of which grew large enough to form islands as early as 15 million years ago. Meanwhile, movement of the two tectonic plates was also pushing up the sea floor, eventually forcing some areas above sea level.
ground_truth: In the last million years since the Late Miocene
sub_queries: What is Tebicuary River a tributary of? Answer: Paraguay River
Which continent is Paraguay River on? Answer: South America
when did South America take form that it has today Answer: In the last million years since the Late Miocene