Quagga

A subspecies of the Plains Zebra, the quagga was hunted to extinction in the late 19th century. Its unique coloring—striped in the front like a zebra and solid brown in the rear—made it a target for trophy hunters.
Cause of Extinction: Overhunting.
Efforts to selectively breed zebras with quagga-like traits are ongoing, but the original quagga is lost forever.