This topic will be designed about the numerous incoherences in the ranges of many species and taxa. Many examples can be brought in mind, but I begin with two problems in the worldwide repartition of some well-known birds : why do the Cranes exist in Eurasia, Africa, Australia and North America, but not in South America, where there are many swamps, grasslands and savannas that would be suitable for these birds ? conversely why there isn't any Stork species in North America, while several species live in Eurasia, Africa and even South America ? [I talk about the true Storks, belonging to the genus Ciconia] I may post future messages about other incoherences in the future.
There are storks in North America, Wood Storks (I know you said Ciconia only, but you also said storks are in South America, which is not true of Ciconia).
Obviously I don't understand really the presence of Maguari Storks in South America if not a single species live in the Northern half of the continent. Are them descendants from African vagrants (given that they look very similar to the Old-World White Storks) ? Or from one or more species that lived in North America and that went extinct in a more or less recent past ? Another hypothesis ?
I suspect it is likely that they are close kin to the La Brea Stork (Ciconia maltha) of North and Central America, which went extinct at the end of the Pleistocene; either way, the fact that the Maguari Stork is resident in South America and is classified within Ciconia demonstrates that @birdsandbats was incorrect to claim the genus is not found in the New World at all
Most of the medium-large mammals of the southern Iberian peninsula occurred historically into northwest Africa; red deer, wild boar, brown bear, eurasian otter, etc. ; those that don't tend to be species that don't extend all the way to the southern edge of the peninsula anyway. Two exceptions are the Iberian lynx, and European badger. A decent, but purely hypothetical, case could be made for competitive exclusion from African felids keeping the Iberian lynx out of the Atlas region in times of lower sea level, but I do wonder why the badger didn't colonise this region.