Prehistoric archaeology had its first pioneers in France led by Boucher de Perthes (the Abbeville school), who excavated fossil bones and stone tools beginning in the late 1820s to early 1830. At about the same time a second group in Denmark led by Worsaae (the Copenhagen school) studied an archaeological interval prior to their historical record, based on museum collections. Though lacking stratigraphical excavation they provided a chrono-typologic basic division into the stone, bronze, and iron ages across the past 3000 years. A third group led by the Italian Scarabelli (the Imola school) introduced the name ancient (prehistoric) archaeology with a field stratigraphic, geologic, petrologic and mapping approach. The discipline of prehistoric archaeology originated almost simultaneously as a multi-vocal result of activity led by these three independent groups.