This is very interesting. It would be neat to see a zoo arranged this way. There aren't many Oceanic species in zoos though it seems.Not really. South and Central America are part of the "New World", but are in the Neotropical Zone- not Nearctic. Likewise with Sub-Saharan Africa- part of the "Old World" but in the Afro-Tropical Zone, not Palearctic. If you are only looking at the northern/colder weather areas, then yes- it is a hemispheral split between Nearctic and Palearctic, but both hemispheres have multiple zoogeographic zones on them. Think of zoogeographic zones as where animals could easily travel- as the distinctiveness of wildlife in each area is due to the relative difficulty to travel between zones. For instance, most animals are incapable of crossing the Saharan Desert, making it a logical "barrier" between zoogeographic zone. Likewise with zones separated by seas/waterways, etc. such as the Australasian Zone.