it is interesting to find out what actually all the creatures in Cyrodill belong to, because some of them are a very confused kingdom

Let see

Human Imperial, Redguard and Nord
Surely they are human of different races and mammals, unless the developer says otherwise.

Human Breton
i am not sure about Breton, they do look like human, but in their art work (i saw somewhere) they are some sort of hybrid. Breton are mixture of elves and human. They are alien-human hybrid. See below.

Elves
They are humanoid, but have pointed ears, long faces, various colors of skins, mostly yellow and dark blue. I am not sure if they are mammals, but sure they are not reptilians. I can say they are aliens.

Khajit
They are mammals no doubt from cat family.

Argonian
Reptilian no doubt. They are lizards.

Orc
They are humanoid, green skinned, pig/boar-like faces and big body. It seems to be they are the mixture of reptiles and mammals hybrid.

Goblins
Similar like Orc, they seems to be a mixture of mammals and reptilians. Or maybe they are reptilian-alien hybrid

Imps
they are small, humanoid, green skinned, have wings. They are alien-reptilian hybrid.

Clanfear
They are dinosaur-like creatures, for sure they are reptilian.

Daedra
They are humanoid, have horns, live in other dimensions. They look like demons. Maybe they are warm blooded, but can't categorized as mammals. They are the unknown.

Trolls
I don't know

Atronach
I don't know

Scamps
Humanoid, look like Goblins, maybe reptilian-alien hybrid

Mudcrabs
They are crustacean no doubt

Rats
Mammals for sure

Bear
Mammals for sure

The wonderful thing about The Elder Scrolls is that not everything can be related to real-life. For example, what can we compare a Minotaur to? What about Dremora or trolls?

Also, a side-note: scamps, atronachs and clannfear are all Daedra

Pretty much this, also Orcs are Elves

yeah...but what kingdom they could be?

For sure, Imperial, Reguard and Nord are Homo Sapien, unless the developer says otherwise. I am not sure about Breton, because they are hybrid.

Minotaur maybe mutan of a bull.

There must be some biological explanation on creatures

I would say that the fact that the world is filled with magic would open up for the possibility that many of the creatures and races would not be possible to explain with science as we know it.

The races are decendants of the Hist(Atgonian) and the Ehlnofey(the mer and men).
The Bretons are a result of generations of interbreeding between Aldmer and Nedes.
The Khajiit is supposed to have been mer, but somehow Azura(I think it was Azura) changed them.

I think it would be interesting if add new major/minor skill, Biology. So we can study the creatures, the ecosystem, creature behavior, what they eat, where they sleep, their habitat and so on.

We have Alchemy, why not Biology?

Niza, have you read some of the books that you find in the game? You might find some of them interesting. There’s a lot going on in Tamriel that has nothing to do with real-world biology.

Nords, Imperials and Bretons all come from Nedes. Bretons are just Nede with some Aldmer mixed in. Redguards are a completely separate human race.

I actually like that because its so mystical and magical, that there isn't simply the homosapiens race. That it actually embraces other mythological races, regardless if they're humanoid or not. It makes role playing much more interesting that I don't have to relate it to real life, but thats because I spend so much time studying in real life I like a place totally magical to escape to...

So who are the women descended from?

Wait what am I saying, we were all created perfect to begin with. We do not need an ancestor to have evolved from.

The most worrying aspect of Tamriel's ecosystem is the high ratio of carnivorous predators to herbivores. And I'm not sure which the rats belong to!

yeah, food chain is confusing, i never see wolves chasing deers, wolves only attack character and bandits (human, human hybrid, Orc, Khajit and Elves), so deer is not in their food chain

I can assume rats eat cheese wedges and all those scattered vegetables.

i don't know what Mudcrab eat, they attack anything but they don't eat them. i saw a mudcrab attacking and kill a horse....but since Nirnroots usually found near beaches, maybe, i say maybe, they eat Nirnroots

Goblins eat human, because there will always be human skeleton in their nest...



i try to read them all, but it just goes...blah blah blah blah....then i goes.....