I find these little misteries very interesting!
The Papo platypus, is number 56011 and belongs to Wildlife collection. :)
In Papo. numbers started with 56, usually belong to Aquatic Animals collection. For example, 56010 is a hammerhead shark.
It is not strange to think in a platypus as an Aquatic animal, though it is not normal to see it in a sea life collection. So, or Papo was planing to place it in the wrong series, or this number was not previously assigned to a platypus. I like these kind of reflections but I am a little crazy anyway.
For a long time, I was curious why the Mojo Iberian lynx, 387064, was between a donkey 387063 and a mute swan 387065!
Both from farm series. Then, I found in a old topic of our forum, that Robert found a supposed Mojo peacock with the number that later was used to the lynx.