Toruk Evolution

[Nìmwey]

Of course they are different species. Even the Ikran and Ikranay are different species, and the only difference there is size.
The scientific name of the Toruk is Leonopteryx rex, meaning Leonopteryx is the genus, rex is the species. Sadly we don't have a scientific name of the Ikran.

But if we put it like this... (warning, boring taxonomy lesson ahead; I use parrots since I know them.
These two parrots are both macaws. One is an Ara ararauna, the other an Ara macao. They are in the same genus, but not the same species.
These two are also both macaws. Ara ararauna and Diopsittaca nobilis, meaning, different genuses.

This is one cockatoo and one macaw. They are different species, yes, but so much more than that. The cockatoo is a Cacatua alba, subfamily Cacatuinae, family Cacatuidae, ordo Psittaciformes. The macaw is an Ara chloroptera, tribus Arini (there is no tribus in family Cacatuidae), subfamily Psittacinae, family Psittacidae, ordo Psittaciformes. They are THAT far from each other, different families even.

So the Banshee and the Leonopteryx - having very different sizes, headshapes, wings, even number of limbs - are definitely far off each other, maybe/probably more so than cockatoos are to true parrots, like in my example.

I'm sure Cameron has a lot more species on Pandora than the 22-23 we know of, since it's impossible to show the whole ecosystem in just one movie. (But he can't have created as many species as there are likely to be on the whole planet/moon, I mean, there are millions of different species on Earth, and it's likely it's the same on Pandora.)