Makes sense the bearded men with burning eyes would opt for Hispanic surnames - the people of Spain were already a mixed race with a large genetic contribution from the Moors and Berbers, the most westerly of the Islamic tribes. Much of the Spanish language, in fact, has Arabic roots, through the Moors, and Islam was not formally rooted out of Spain until about the time Columbus set sail for the New World.
Interesting. This bears watching in other Hispanic areas.