Ursus ursinus vs Melursus ursinus

Ursus ursinus and Melursus ursinus both are nouns.

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

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

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

Other synonyms of Ursus ursinus include sloth bear.

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