Pokémon Diamond and Pearl added 107 new Pokémon to the series.
The games were first released in Japan on September 28, 2006, for the Nintendo DS. They began Pokémon’s fourth generation and introduced the Sinnoh region, whose geography was inspired by Hokkaido and nearby areas of Japan.
Diamond and Pearl expanded the Pokédex from 386 species to 493. Their new Pokémon included the legendary mascots Dialga and Palkia, as well as many evolutions and pre-evolutions connected to species from earlier generations.
The Nintendo DS hardware enabled new features, including touch-screen functions and Nintendo Wi-Fi Connection support. Players could trade and battle online, a major step beyond the local link features of the Game Boy era. The number 107 is distinct from Generation II’s 100 new species and Generation III’s 135, making generation-by-generation counts a useful way to distinguish Pokémon milestones.