A species of oryx which formerly inhabited all of North Africa. It has a long taxonomic history since its discovery in 1816, by Lorenz Oken, as Oryx algazel. This oryx is just over 1 m (3.3 ft) in height and may weigh up to 200 kg (440 lb). Now it is extinct in the wild.

The scimitar oryx formed herds of mixed sexes of up to 70 members, with the bulls usually guiding the herds. They inhabited semideserts and deserts, and were adapted to live in the extreme heat - with their efficient cooling mechanism and very low requirement of water. Scimitar oryx mainly feed on foliage - grasses, succulent plants and plant parts, during the night or early morning. Births peak between March and October. After a gestational period of eight to 9 months, one calf is born, and soon after, the female experiences a postpartum estrus.

In Ancient Egypt, the scimitar oryx was domesticated and believed to be offerings for gods and used as food. Wealthy people in Ancient Rome also bred the oryx. The use of their valuable hides began in the mediaeval Age. The unicorn myth may have originated from sightings of an injured scimitar oryx.

Once widespread in northern Africa, now it has been classified as extinct in the wild by the IUCN. They originally began declining due to climatic changes; later, they were hunted extensively for their horns. Today, they are bred in captivity.

The nomenclature of this animal has undergone many changes since its discovery in the early 19th century. It was first described by Lorenz Oken, a German naturalist, in 1816 as Oryx algazel. But it was considered inappropriate by Sir John Ellerman (Second Baronet), English shipowner, natural historian and philanthropist, and Terence Morrison-Scott, a British zoologist and was replaced by Oryx tao in 1827. In 1827, another species name leucoryx was used, but was soon assigned a synonym to the Arabian oryx (Oryx leucoryx). All these names were soon replaced by Oryx dammah a decade later by Philipp Jakob Cretzschmar, a German physician. Though the oldest name Oryx algazel was reintroduced after the name leucoryx failed, but, in 1951, Ellerman and Morrison-Scott realised the name was not suitable. Finally in January 1956, the International Trust for Zoological Nomenclature accepted Oryx dammah as the scientific name, though many papers published shortly after created confusion by using other names.

The scimitar oryx has 58 chromosomes. It has one pair of large submetacentric autosomes and 27 acrocentric autosomal pairs. The X and Y chromosomes are the largest and smallest acrocentrics. In the first molecular study on this species, genetic diversity among European, North American and some other captive groups was observed. A deep divergence was marked within the mitochondrial DNA haplotypes. The estimated divergence time was traced back to 2.1 to 2.7 million years. The populations increased approximately 1.2 and 0.5 million years ago.

In another study to note genetic differences between Oryx species, karotypes of Oryx species - namely O. gazella gazella, O. g. beisa, O. g. callotis, O. dammah and O. leucoryx - were compared with the standard karotype of Bos taurus. The number of autosomes in all karotypes was 58. The X and Y chromosomes were conserved in all the five species. O. g. gazella was a different from other Oryx species due to the fixed 2;17 centric fusion, which reflected that it has been geographically isolated from other Oryx taxa, and agrees with the classification of O. gazella and O. beisa as distinct species. After the analysis, it was concluded that sterility in hybrids (produced due to interbreeding in Oryx species) had not yet developed and there was viability.