What is really funny is the abundance of non-fossil dinos introduced before gen 4, like Meganium and Sceptile. So a bunch of Dinos died out (Rampardos, Tyrantrum etc) but Sceptile and Meganium survive and go all the way to the present day? xDFine, in the name of SCIENCE(!) I'll agree the first (fossil) dino Pokemon weren't introduced until Gen IV.
Touche xD.
But just cause I agree with ya doesn't mean I'm not going to troll a little. ;P
Well I personally see it as Anomalacaris and Eurypterids have a lot of features to work with, so more to muck with. Megalodon and Mosasaurs are just kinda, plain and lacking features. I mean one is just literally a big version of a Great White.So why can't they "pokemonify" the Mosasaur and/or Megalodon?
I mean they could pokemonify them and would if they use them, but a lot more creatures have more to work with, like Dunkelosteus.