The terms "Paleolithic" and "Neolithic" were introduced by John Lubbock in his work Pre-historic Times in 1865.
The additional "Mesolithic" category was added as an intermediate category by Hodder Westropp in 1866.
Westropp's suggestion was immediately controversial.
 A British school led by John Evans denied any need for an intermediate: the ages blended together like the colors of a rainbow, he said.
A European school led by Louis Laurent Gabriel de Mortillet asserted that there was a gap between the earlier and later.

Edouard Piette claimed to have filled the gap with his naming of the Azilian Culture.
Knut Stjerna offered an alternative in the "Epipaleolithic", suggesting a final phase of the Paleolithic rather than an intermediate age in its own right inserted between the Paleolithic and Neolithic.

By the time of Vere Gordon Childe's work, The Dawn of Europe (1947), which affirms the Mesolithic, sufficient data had been collected to determine that a transitional period between the Paleolithic and the Neolithic was indeed a useful concept.
However, the terms "Mesolithic" and "Epipalaeolitic" remain in competition, with varying conventions of usage.
In the archaeology of Northern Europe, for example for archaeological sites in Great Britain, Germany, Scandinavia, Ukraine, and Russia, the term "Mesolithic" is almost always used.
In the archaeology of other areas, the term "Epipaleolithic" may be preferred by most authors, or there may be divergences between authors over which term to use or what meaning to assign to each.
 In the New World, neither term is used (except provisionally in the Arctic).

"Epipaleolithic" is sometimes also used alongside "Mesolithic" for the final end of the Upper Paleolithic immediately followed by the Mesolithic.
As "Mesolithic" suggests an intermediate period, followed by the Neolithic, some authors prefer the term "Epipaleolithic" for hunter-gatherer cultures who are not succeeded by agricultural traditions, reserving "Mesolithic" for cultures who are clearly succeeded by the Neolithic Revolution, such as the Natufian culture.
Other authors use "Mesolithic" as a generic term for hunter-gatherer cultures after the Last Glacial Maximum, whether they are transitional towards agriculture or not.
In addition, terminology appears to differ between archaeological sub-disciplines, with "Mesolithic" being widely used in European archaeology, while "Epipalaeolithic" is more common in Near Eastern archaeology.
The terms "Paleolithic" and "Neolithic" were introduced by John Lubbock in his work Pre-historic Times in 1865. The additional "Mesolithic" category was added as an intermediate category by Hodder Westropp in 1866. Westropp's suggestion was immediately controversial.  A British school led by John Evans denied any need for an intermediate: the ages blended together like the colors of a rainbow, he said. A European school led by Louis Laurent Gabriel de Mortillet asserted that there was a gap between the earlier and later.
Edouard Piette claimed to have filled the gap with his naming of the Azilian Culture. Knut Stjerna offered an alternative in the "Epipaleolithic", suggesting a final phase of the Paleolithic rather than an intermediate age in its own right inserted between the Paleolithic and Neolithic.
By the time of Vere Gordon Childe's work, The Dawn of Europe (1947), which affirms the Mesolithic, sufficient data had been collected to determine that a transitional period between the Paleolithic and the Neolithic was indeed a useful concept. However, the terms "Mesolithic" and "Epipalaeolitic" remain in competition, with varying conventions of usage. In the archaeology of Northern Europe, for example for archaeological sites in Great Britain, Germany, Scandinavia, Ukraine, and Russia, the term "Mesolithic" is almost always used. In the archaeology of other areas, the term "Epipaleolithic" may be preferred by most authors, or there may be divergences between authors over which term to use or what meaning to assign to each.  In the New World, neither term is used (except provisionally in the Arctic).
"Epipaleolithic" is sometimes also used alongside "Mesolithic" for the final end of the Upper Paleolithic immediately followed by the Mesolithic. As "Mesolithic" suggests an intermediate period, followed by the Neolithic, some authors prefer the term "Epipaleolithic" for hunter-gatherer cultures who are not succeeded by agricultural traditions, reserving "Mesolithic" for cultures who are clearly succeeded by the Neolithic Revolution, such as the Natufian culture. Other authors use "Mesolithic" as a generic term for hunter-gatherer cultures after the Last Glacial Maximum, whether they are transitional towards agriculture or not. In addition, terminology appears to differ between archaeological sub-disciplines, with "Mesolithic" being widely used in European archaeology, while "Epipalaeolithic" is more common in Near Eastern archaeology.
Mesolithic