#345 is Lileep, you need to find a root fossil by mining underground.
In the Sinnoh Pokedex it is Feebas and Milotic, however, in the National Pokedex it is Omanyte and Omastar.
Happiny in the sinnoh pokedex and in the national pokedex number 96 is drowzee
IN Pokemon platinum you find this Pokemon on route 201(after you get the national pokedex you put fire red version into your DS)and he will appear.Samething with Pokemon pearl and diamond.
You have to find all of the Pokemon in Sinnoh.
You must have the National PokeDex to capture Heatran.
in diamond, pearl and platinum it is heracross
I believe you meet him after completing the Sinnoh Pokedex. Then he will update your pokedex to national.
You cannot find Mewtwo in Pokémon Platinum. you have to migrate it tto the pal park after you get the national pokedex.
Eevee's number in the national Pokedex is #133. If you don't know what the Pokemon's number is then go to pokemondb.net/pokedex/national It is a great site to find Pokemon's number!!
On the national pokedex Groudon is number 383.You can not find Groudon on the Sinnoh pokedex.
you cant find it, you have to see all the Pokemon sapphire.
check the number in your NATIONAL pokedex