The origins and classification of the Fulani remains controversial; one school of thought is of the opinion that the Fulani cattle are truly long-horned zebus that first arrived in Africa from Asia on the east coast; these are believed to have been introduced into West Africa by Arab invaders during the seventh century, roughly about the same time that the short-horned zebus arrived into East Africa. This theory is supported by the appearance of the skull as well as the thoracic hump of the Fulani cattle.