Complex sentence: In Greek mythology, satyrs are a troop of half-man, half-goat male companions of Pan and Dionysus-- "satyresses" were a late invention of poets--that roamed the woods and mountains.
Split into simpler sentences: In Greek mythology, satyrs (,, Greek saturos σάτυρος) are a troop of male companions of Pan and Dionysus. "Satyresses" were a late invention of poets--that roamed the woods and mountains.