Oryx is a genus consisting of four large antelope species called oryxes. Their pelage is pale with contrasting dark markings in the face and on the legs, and their long horns are almost straight. The exception is the scimitar oryx, which lacks dark markings on the legs, only has faint dark markings on the head, has an ochre neck, and has horns that are clearly decurved.
Oryx
East African oryx in the Awash National Park, Ethiopia
The term antelope refers to numerous extant or recently extinct species of the ruminant artiodactyl family Bovidae that are indigenous to most of Africa, India, the Middle East, Central Asia, and a small area of Eastern Europe. Antelopes do not form a monophyletic group, as some antelopes are more closely related to other bovid groups, like bovines, goats, and sheep, than to other antelopes.
Antelope
A bull sable antelope among the trees in the African savanna
Illustration from The History of Four-footed Beasts (1607)
Blue duiker (Philantomba monticola) skeleton on display at the Museum of Osteology.