The Collaborative International Dictionary of English v.0.48:
Melursus \Melursus\ prop. n. A genus of mammals including the sloth bears; in some classifications not a separate genus from Ursus. Syn: genus Melursus. [WordNet 1.5]WordNet (r) 3.0 (2006):
Melursus n 1: sloth bears; in some classifications not a separate genus from Ursus [syn: Melursus, genus Melursus]