Scholars have found it difficult to determine exactly when the Paleoindian period ends .
The Archaic begins , but it is generally linked with changing climate associated with the transition from the Pleistocene to the Holocene epochs , and absence of extinct Pleistocene animals .
Scholars have found it difficult to determine exactly when the Paleoindian period ends and the Archaic begins , but it is generally linked with changing climate associated with the transition from the Pleistocene to the Holocene epochs , and absence of extinct Pleistocene animals .