Arsinoitheres were superficially rhinoceros-like herbivores that lived during the Late Eocene and the Early Oligocene of North Africa from 36 to 30 million years ago, in areas of tropical rainforest and at the margin of mangrove swamps.

[1] While the Faiyum Oasis is the only site where complete skeletons of Arsinoitherium fossils were recovered, arsinoitheriids have been found in southeastern Europe, including Crivadiatherium from Romania, and Hypsamasia and Palaeoamasia from Turkey.

The generic name Arsinoitherium comes from Pharaoh Arsinoe II (after whom the Faiyum Oasis, the region in which the first fossils were found, was called during the Ptolemaic Kingdom),[2] and the Ancient Greek: θηρίον theríon "beast".

[4][5] It weighed 2.5 tons, only slightly smaller than the modern white rhino and due to the similar features and sizes, Arsinoitherium is commonly thought[by whom?]

Fossils are found in sediments deposited in coastal swamps and warm, humid, heavily vegetated lowland forests across what is now Africa and Arabia.