The scimitar-horned oryx is a North African desert and Sahel antelope historically native to Morocco, Tunisia, Algeria, Libya, Egypt, Mauritania, Mali, Niger, Chad, and Sudan. Adults weigh about 220ā460 pounds and may stand up to about 4.6 feet at the shoulder. They are mostly white with a reddish-brown neck and chest, facial markings, dark tail tuft, and long backward-curving horns in both sexes. They are highly desert-adapted and can tolerate extreme heat and limited water. Scimitar oryx entered U.S. conservation and ranch-breeding programs in the 1960sā1970s and were documented in Texas by 1979. (National Zoo) (CBS News)