Tom Holtz writes: "bears from paleotropical
and neotropical rainforests can be quite hairy.
Please note, though: that was just a reminder, and not an excuse to start
drawing shaggy rexes! "
Assuming tyrannosaurs were phylogenetically likely to be feathered, why would they lose them?
Why can't big ceolurosaurs have feathers? Ostriches, at 150kg are already too big to need feathers for insulation, especially given the climate they live in. (mass homeothermy starts around 100kg, Colbert 1946.)
Many other birds weighed much more, up to 500kg! So why can't T-rex be feathered?
(Once again, thanks everyone for your replies. Got one from Tom Holtz! How much better can life get?)