As per the Wiktionary article the origin of the world is Russian:
From obsolete Russian ма́мант (mámant), modern ма́монт (mámont), probably from a Uralic language, such as Proto-Mansi *mē̮ŋ-ońt (“earth-horn”). Possibly influenced by behemoth
But if we check the Wikipedia article the first sentence would be:
A mammoth is any species of the extinct elephantid genus Mammuthus
I have not found translation for the word Mammuthus (Google translate is not the best academic source), but I assume this is a Latin word since it is a name for genus.
The thing which confuses me is that Latin has its own word for "mammoth", while Wiktionary claims its Russian origin. Does it mean that Latin inherited it from Russian? Or did they both have its own words, but English somehow inherited this word from Russian instead of Latin?
It looks like I miss something.