<P> Before the 20th century, the Zhou dynasty (1046--256 BC) was the earliest Chinese dynasty that could be verified from its own records . However, during the Song dynasty (960--1279 AD), antiquarians collected bronze ritual vessels attributed to the Shang era, some of which bore inscriptions . These types of early inscriptions were later traced to the Yinxu site in the Yellow River valley . </P> <P> There are several important Shang sites in the Yellow River valley . </P> <P> In 1899, several scholars noticed that Chinese pharmacists were selling "dragon bones" marked with curious and archaic characters . These were finally traced back in 1928 to a site (now called Yinxu) near Anyang, north of the Yellow River in modern Henan province, where the Academia Sinica undertook archeological excavation until the Japanese invasion in 1937 . </P> <P> Archaeologists focused on the Yellow River valley in Henan as the most likely site of the states described in the traditional histories . </P>

What type of dynasty was the shang dynasty