Resumen de Phylogenetic and Paleobiogeographical Trends in the Foraminiferal Genus Amphistegina
A large number of fossil and Recent Amphistegina from low- and mid-latitudes throughout the world have been examined.
Amphistegina is an exclusively Cainozoic form. The holotype of the supposed Carboniferous species A. minuta belongs to the Recent species A. radiata.
On the basis of diagnostic characters and evolutionary trends, 17 morphological forms or species are discussed, and arranged in a phylogenetic scheme.
Palaeogeographical considerations point to changing Amphistegina provinces through the Tertiary. In Recent times, three Amphistegina provinces can be distinguished: Indo-Pacific, Atlanto-Caribbean and European. While the two last are dominated totally by one species, respectively A. gibbosa and A. lobifera, the Indo-Pacific province is characterized by changing associations of several other species.
