BlueDev on the background behind Argonians:
From the Elder Scrolls Forums, posted 04/12/01
Finally, a question about my friends the Argonians.
No, the Argonians aren't all lizardy because of that troublesome blight. The Argonians are lizards because, well, that's what nature intended...sort of. As to how they came to be that way, what the story is behind them...there's more to be discovered. I will tell you that there's more to the Hist than has been told, and they and the Argonians have a much deeper relationship than previously thought. Shows you what happens when you let a Dunmer try to explain these things. Black Marsh is, sadly, far too unexplored, leaving the enigmatic Argonians shrouded in a bit too much mystery for my liking. More to come on this soon, hopefully. Guess that sort of answers your question.
...This 'tells' one very little, but indicates a number of things. BlueDev (Mark Nelson) clarifies past inaccuracies...
BlueDev on what "Hist" is referring to:
From the Elder Scrolls Forums, posted 04/16/01
This is neither a typo nor bad grammar. The PGE will tell you that the Hist are "a relatively intelligent strain" of Argonians. The Guide contains many inaccuracies, and this is one of them. You will also notice that the Guide mentions "a certain type of spore tree" that native Argonians might worship. Speaking generally, it is these trees that are the Hist. As for the relationship, I'm not talking yet.
Just by reading that it seems to me that the Argonians are not ACTUALLY Hist, nor did they directly evolve from them. It seems that their creation however, was joined together in some fashion. Perhaps they are the keepers of these trees. Perhaps the lick they give helps the trees reproduce. Who knows?? We'll just have to wait for more lore
Perhaps the new books will shed some light on them!
On the dinosaur debate that was raging, we know too little to actually give a confident answer to the cold/warm blooded question, but in all likeliness by looking at birds and looking at reptiles, we can assume that there were both warm and cold blooded dinosaurs. The only dinosaurs to survive the fallout of the Yucatan impact, would have most likely been cold blooded with slow metabolisms, so the evidence we see today isn't very telling.