New fossil record of the Lactoridaceae in southern South America: a paleobiogeographic approach.

GAMERRO, J.C.; BARREDA, V.

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY

Año: 2008 vol. 158 p. 41 - 50

0024-4074

Lactoridaceae is a monotypic family confined to the Masatierra Island, Juan Fernández archipelago, in the Pacific Ocean. It grows in the understorey of a subtropical montane rain forest. Lactoridaceae most likely originated in southern South Africa in the Cretaceous, with the oldest records in the Turonian-Campanian, and reached its widest paleogeographic distribution by the Maastrichtian, extending into Australia, India, Antarctica and North and South America. Here we report a new fossil find of lactoridaceous tetrads from the Early Miocene of eastern Patagonia, southern South America. This record is the youngest, and geographically one of the closest to the extant Lactoris distribution area. Patagonian fossil material shows greater similarities to extantdistribution area. Patagonian fossil material shows greater similarities to extant L. fernandeziana Phil. than any other described morphotaxon. The family may have migrated into South America either via Africa (through the Atlantic Ocean) or Antarctica by the Maastrichtian, growing in eastern Patagonia up to the Early Miocene. Arid conditions established in this region by the Middle-Late Miocene onwards would have determined the restriction of forests to the western lands. Lactoridaceae may have followed a similar migration pattern towards the Pacific coast of South America. The shifting of Lactoridaceae towards the Masatierra Island would have occurred in the last 4 Myr, by long distance dispersal episodes (perhaps by birds). Phil. than any other described morphotaxon. The family may have migrated into South America either via Africa (through the Atlantic Ocean) or Antarctica by the Maastrichtian, growing in eastern Patagonia up to the Early Miocene. Arid conditions established in this region by the Middle-Late Miocene onwards would have determined the restriction of forests to the western lands. Lactoridaceae may have followed a similar migration pattern towards the Pacific coast of South America. The shifting of Lactoridaceae towards the Masatierra Island would have occurred in the last 4 Myr, by long distance dispersal episodes (perhaps by birds).