The phylogeny of Bromeliaceae and the continental drift.

Bromeliaceae is an almost completely neotropical family, with the only exception of Pitcairnia feliciana Harms and Mildbraed, known only for few localities in western Africa. The resulting unbalanced areal disjunction may represent a case of gradual vicariance formation (with the separation of P. feliciana from the rest of Bromeliaceae as ancient as the Atlantic Ocean. Another possible explanation considered by many authors is a long distance dispersal through birds migrating from tropical America to tropical Africa. Nevertheless, most common bird migration routes are north-south, rather than west-east. A further possible explanation may be linked to birds capable of south-north migration in America and than able to reach Europe through circumboreal routes (for instance the arctic tern) and from Europe then migrate south towards Africa, with a triangle connection between America and Africa. Such connections would be very rare and, as a matter of fact, it would have occurred only once for family Bromeliaceae.