This issue marks the introduction of the energetic Sonora eagle obverse to regular coinage. It had appeared first on the rare 1851 Culiacan pattern (lot 438), now to be used on 8-Reales for only a few years at Culiacan, and for only 1861 and part of 1862 at Hermosillo. It also appeared on minor gold and silver of Alamos and Guadalupe y Calvo.