Mediportal is a related term of graviportal.

In biology terms the difference between graviportal and mediportal

is that graviportal is of an animal, physically adapted only for moving slowly over land, due to a high body weight; examples include giant tortoises while mediportal is of an animal, physically adapted to spend a substantial amount of time moving slowly over land, usually with a heavy body weight, but also having some characteristics conducive to quick movements when needed; examples include bison, elephants, and rhinoceri.