Why are the Apennines considered part of the Alpine mountain system?

The Apennines are considered part of the Alpine mountain system because they share a common geologic origin and tectonic history with other ranges in the region, such as the Alps, the Dinaric Alps, and the Atlas Mountains.12

Geologically, the Apennines are classified as a younger range formed during the Cenozoic Era as a result of the Alpine orogeny—a period of intense mountain building driven primarily by the northward compression of the African plate into the European plate. This tectonic collision led to the destruction of the Tethys Sea through subduction and the subsequent folding and thrusting of marine sedimentary rocks that now compose the bulk of the Apennine chain.132

Because these ranges were shaped by the same large-scale plate interactions and tectonic phases, they are viewed as part of a single, interconnected mosaic of mountain belts that extends across the Mediterranean region.2