Final answer:
The Atapuerca site with its Oldowan style stone tools and the Vero Man site in Florida, where human and megafauna bones were jointly discovered, solved the issue regarding early human tool usage and interaction with Pleistocene megafauna.
Step-by-step explanation:
The discovery of human-made stone tools associated with Pleistocene extinct megafauna at various archaeological sites has provided significant insights into early human behavior and technologies. Notable among these sites is the Atapuerca site, where Oldowan style stone tools were found, indicative of meat processing activities and suggesting social cooperation through food sharing practices. Additionally, the Vero Man site in Florida revealed human and megafauna bones together, pointing towards human interaction with these large animals. These sites highlight advancements in prehistoric tool-making across different periods, including the refined blade tool industry during the Upper Paleolithic that enabled the construction of more efficient tools.