No creditable macrofossil record of the Fagaceae exists in the Cretaceous deposits and all the Cretaceous microfossil reports remain equivocal and require further study.
In both cases, the researchers have evoked scenarios of Cretaceous vicariance, followed by endemic species radiation within Madagascar and subsequent dispersal from Madagascar to other areas.
The basin tectonic model: it is intermont basin during late Jurassic to early Cretaceous, developed into faulted-lacustrine basin in Eogene, and evolved into depression in Neogene and Quaternary.