What is the origin of Saturnian?

Saturnian “prosperous, happy, or peaceful” derives from the Latin adjective Sāturnius “of Saturn.” The mythological figure Saturn, known to the Romans as Sāturnus and considered an equivalent of the Ancient Greek figure Kronos (Latinized as Cronus), was a Titan and a god of agriculture. The positive aspects of Saturn’s reign, referred to as the “golden age,” are what give Saturnian its meaning. Though Saturnian shares an origin with saturnine, they are almost antonyms; saturnine means “sluggish, gloomy, taciturn” and derives its meaning from astrology, in which the influence of the planet Saturn is associated with negative personality traits (in contrast to the recent Word of the Day jovial). The name Sāturnus is likely of Etruscan origin—compare the name of the Etruscan god Satre—but has long attracted (false) folk etymology hypotheses, such as derivations from Latin satus “sown” or satis “enough.” Saturnian was first recorded in English in the 1550s.