The Abbasid Caliphate differed from others in that it did not have the same borders and extent as Islam. Particularly, in the west of the Caliphate, there were multiple smaller caliphates that existed in relative peace with them.
The major difference between the protist and the animal kingdom is protists are unicellular protozoans and unicellular & multicellular, but animals are multicellular animals.
The animal kingdom is typically divided into two main groups: the invertebrates and the vertebrates. The vertebrates are distinguished by the presence of a backbone, and are the organisms that come to mind when one thinks of an animal: fish, amphibians, reptiles, birds, and mammals.