Melursus ursinus vs Ursus ursinus

Melursus ursinus and Ursus ursinus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Melursus ursinus	Yes	No	No	No
Ursus ursinus	Yes	No	No	No

As nouns, Melursus ursinus and Ursus ursinus are synonyms defined as:

Melursus ursinus and Ursus ursinus: common coarse-haired long-snouted bear of south-central Asia

Other synonyms of Melursus ursinus include sloth bear.

Melursus ursinus (noun)	Ursus ursinus (noun)
common coarse-haired long-snouted bear of south-central Asia	common coarse-haired long-snouted bear of south-central Asia