I believe it is a "Fused" sentence because it includes two main clauses. hope this helps
I think it might be “It introduces the story and sets up the coming events.” I’m not sure so take this with a grain of salt...
Answer:
In the sentence, the phrase of a cave bear functions as an adverb prepositional phrase. An adverb prepositional phrase modifies a verb, adjective, or adverb. It usually tells when, where, how, why, or to what extent (how many, how much, how long, or how far), and under what condition.
Explanation: