Pokemon Diamond Version Exclusives
Seel, Dewgong
Scyther, Scizor
Murkrow, Honchkrow
Larvitar, Pupitar, Tyranitar
Poochyena, Mightyena
Aron, Lairon, Aggron
Kecleon
Cranidos, Rampardos
Stunky, Skuntank
Dialga
Pokemon Pearl Version Exclusives
Slowpoke, Slowbro, Slowking
Pinsir
Misdreavus, Mismagius
Houndour, Houndoom
Stantler
Spheal, Sealeo, Walrein
Bagon, Shelgon, Salamence
Sheildon, Bastiodon
Glameow, Purugly
Palkia
The above Pokemons are available in Platinum too except the underlined ones.
Pokemon Platinum Version Exclusive
Tangela, Tangrowth
Articuno
Zapdos
Moltres
Tropius
Regirock
Regice
Registeel
Heat Rotom
Wash Rotom
Frost Rotom
Fan Rotom
Mow Rotom
Giratina Origin Forme
Shaymin Sky Forme
Following are the Pokemons which are available in both Diamond and Pearl but not in Platinum.
Clamperl, Huntail, Gorebyss
Trapinch, Vibrava, Flygon
Seel, Dewgong
Scyther, Scizor
Murkrow, Honchkrow
Larvitar, Pupitar, Tyranitar
Poochyena, Mightyena
Aron, Lairon, Aggron
Kecleon
Cranidos, Rampardos
Stunky, Skuntank
Dialga
Pokemon Pearl Version Exclusives
Slowpoke, Slowbro, Slowking
Pinsir
Misdreavus, Mismagius
Houndour, Houndoom
Stantler
Spheal, Sealeo, Walrein
Bagon, Shelgon, Salamence
Sheildon, Bastiodon
Glameow, Purugly
Palkia
The above Pokemons are available in Platinum too except the underlined ones.
Pokemon Platinum Version Exclusive
Tangela, Tangrowth
Articuno
Zapdos
Moltres
Tropius
Regirock
Regice
Registeel
Heat Rotom
Wash Rotom
Frost Rotom
Fan Rotom
Mow Rotom
Giratina Origin Forme
Shaymin Sky Forme
Following are the Pokemons which are available in both Diamond and Pearl but not in Platinum.
Clamperl, Huntail, Gorebyss
Trapinch, Vibrava, Flygon