Rhinocerine is a somewhat confusing word, in that it has drastically changed its meaning over time. As of 1970, the Oxford English Dictionary had only one brief definition, "infesting a rhinoceros". I'm not certain why this was important enough to make it into the public eye in the late 1800s, but it is perhaps noteworthy that Gyrostigma rhinocerontis (formerly Gyrostigma pavesii) has the distinction of being the largest botfly in Africa.
Modern dictionaries, if they bother to include the word at all, have a tendency to define it as 'resembling a rhinoceros'; this very much matches the common usage. If, however, one is a purist, there are a number of words that one can use to mean 'related to or resembling a rhinoceros'. The OED lists 'rhinocerotic' as their prefered term, and the synonyms rhinoceroid and rhinocerontine redirect there. (Modern usage seems to be leaning towards preferring rhinocerontine as a technical term, and rhinoceroid as a term more often used in works of fantasy). There is also the flippant and informal rhinocerical, which should be used figuratively or not at all.