The fourth generation introduced 107 new Pokémon.
This generation began with Pokémon Diamond and Pearl, released for the Nintendo DS in Japan in 2006 and internationally in 2007. Its new species ran from Turtwig through Arceus in National Pokédex order, bringing the total number of known Pokémon to 493.
The generation introduced the Sinnoh region and expanded several systems, including the physical–special move split, which classified moves individually rather than assigning categories only by type. It also added new evolutions for older Pokémon, including Electivire, Magmortar, and Togekiss.
The figure 107 is sometimes confused with the number of Pokémon obtainable in a particular version or with the size of a later generation. It refers specifically to newly introduced species in the fourth generation as a whole, including Pokémon first appearing across Diamond, Pearl, Platinum, HeartGold, and SoulSilver-era material.