salamance
Dialga is # 149 in the pearl pokedex
it is dialga
In Diamond & Pearl's version of the Sinnoh Dex, Pokémon #149 is Dialga.
Pokemon Number 149 (Dialga) Cannot be found in Pokemon Pearl, he is only available in Pokemon Diamond, where as Number 150 (Paulkia) cannot be found in Pokemon Diamond. If you need to fill the spot to complete the PokeDex, you can see #149 from a lady in Celestic Town.
Dragonite is #149 in the national pokedex, and it is a Dragon-Flying type Pokemon.
I think it is dialga to get diagla in your pokedex i think you go to the big house north of ceslestic town and talk to an old lady and she'll show you a picture and it will be added to your pokedex
In the Sinnoh Dex, #149 is Dialga. You encounter it in Mt. Coronet in Diamond, talk to the elder of Celestic Town in Pearl, and will be registered in your pokedex along with Palkia once you enter the Distortion World in Platinum.
Dialga
On the sinnoh pokedex it is Dialga; on the national pokedex it is Dragonite.
You'll need to evolve Dragonair to get Dragonite (#149)
dragonite is in the national dex dialga is in the original dex
The Pokemon that are in Pokemon blue are at least the first 149 Pokemon in the pokedex. I'm not sure about Mewtwo or Mew though