The last sentence "Chloe loves to do research about dinosaurs, and she has a large dinosaur collection" is an example of a compound sentence for two reasons. The first is that the units are of the same level, in this case there are two clauses. The second reason is that the clauses arw linked by the coordinating conjuction 'and'. The other sentences are linked by subordinating conjuctions, in this case 'if', 'especially' and 'because'.
