At least basally, the tyrannosauroids should be feathered to some degree
at stage 1 or II elements. However, there is reason to suspect this was
not sustained at large size, which is coincident in extant environments
temperature-biased. Ostriches are fully "fluffed-out" at hatching, but
during maturity, their legs become almost entirely bare from ankle to hip.
Integumnet in the adult or the juvenile does not hold true during the
moult. This might be of some issue in reflecting wether or not adult
tyrannosaurids were feathered or not. The idea that the arms bore full
stage IV-V remiges is unlikely given the phylogenetic bracketing.