Complex sentence: Additionally, the top of the mound produced 65 sherds of prehistoric pottery, but as the Archaic peoples who inhabited the site have shown no evidence of producing their own pottery, these sherds are believed to have been the work of later peoples.
Split into simpler sentences: Additionally, the top of the mound produced 65 sherds of prehistoric pottery. As the Archaic peoples who inhabited the site have shown no evidence of producing their own pottery, these sherds are believed to have been the work of later peoples.