In the Pangea, small foraminifers (endothyrids) are useful tools for studying the stratigraphy of the late Paleozoic. However, they have been largely ignored in South America. This article reports for the first time their widespread occurrence in the subcontinent and illustrates representatives of 21 families encountered from the Early Pennsylvanian (Bashkirian) to the Early Permian (Artinskian). Fifty-five foraminiferal genera are recognized in three basins of Ecuador–Bolivia and enable us to establish a crude zonation. The fauna is nonendemic, all genera being previously known from Eurasia and North America. There are also a number of taxa derived from the Arctic Realm (Sverdrup Basin and Arctic Alaska). In association with the microflora of green and red algae, the microfauna suggests temperate warm conditions. This indicates that since the Middle Carboniferous, warm climatic oscillations affected the South American part of Gondwana.