The Paleolithic era is followed by the Mesolithic. The date of the Paleolithic–Mesolithic boundary may vary by locality as much as several thousand years. During the Paleolithic period, humans grouped together in small societies such as bands, and subsisted by gathering plants and fishing, hunting or scavenging wild animals. The Paleolithic is characterized by the use of knapped stone tools, although at the time humans also used wood and bone tools. Other organic commodities were adapted for use as tools, including leather and vegetable fibers; however, due to their nature, these have not been preserved to any great degree. Surviving artifacts of the Paleolithic era are known as paleoliths.
- McClellan (2006)۔ Science and Technology in World History: An Introduction۔ Baltimore, Maryland: JHU Press۔ https://books.google.com/?id=aJgp94zNwNQC&printsec=frontcover#PPA6۔