After that, four to six faunal assemblages, the so-called African Faunal Strata (AFSs) can be distinguished. The isolation of Africa was broken intermittently by discontinuous "filter routes" that linked it to some other Gondwanan continents (Madagascar, South America, and perhaps India), but mainly to Laurasia. Interchanges with Gondwana were rare and mainly "out-of-Africa" dispersals, whereas interchanges with Laurasia were numerous and bidirectional, although mainly from Laurasia to Africa. Despite these connections, isolation resulted in remarkable absences, poor diversity, and emergence of endemic taxa in Africa. Madagascar separated from continental Africa during the break-up of Gondwanaland early in the Cretaceous, but was probably connected to the mainland again in the Eocene.