Claim: The Ischigualasto formation (a Late Triassic fossiliferous formation) is exposed in the Ischigualasto Provincial Park of La Rioja and San Juan Provinces, while in the neighboring Talampaya National Park, the formation is thin and covered by recent sediments.
Evidence: The Ischigualasto Formation is a Late Triassic fossiliferous formation and Lagerstätte in the Ischigualasto-Villa Unión Basin of the southwestern La Rioja Province and northeastern San Juan Province in northwestern Argentina. The formation crops out in the in 1967 established Ischigualasto Provincial Park, which was designated a UNESCO World Heritage Site in 2000. In the neighboring Talampaya National Park, the formation is thin and covered by recent sediments.