This is one of my best pics and the replacement for this pic Tarbosaurus bataar
I personally think it is a species of Tyrannosaurus because I find the argument that they lived on different continents to be weak. Wolves and dingos are even the same species and they live on different continents and it only took a brief drop in sea level to allow dingos to migrate to Australia and such a drop happened at the end of the cretaceous which likely also contributed to the extinction of the dinosaurs which really does appear to be gradual and it's even apparent when you are near the boundary because you see hardly a scrap of bone and ones that are tend to be redeposited. You learn a lot when you go out and actually do stuff in the field. I suggest doing so yourself though not with Marmarth research foundation.
It may be the case that the underside was scaly and the upside was fluffy
[EDIT: heh, those scale samples are not even from Tarbosaurus, so it's kinda just artistic interpretation]
I'm just much more of a basal sauropodomorpha, early theropoda or Abelisaur fan.
I'm going to be honest though, and this is a bit off subject of your art, but I've always found it a bit questionable seeing the Big Tyrannos having feathers in their adult stage. While as young and definitely their ancestral line probably had feathers, with the really big ones the feathers seem out of place; like something that could potentially make them overheat, especially Bataar since it came from the Gobi Desert and surrounding region.
Still, this pic is great. Definitely going to look through more. ^^