T-rex again

A new theory about T-Rex suggests they had short arms to keep them out of the way of each other when chomping on a carcass. I'd wondered if it was to keep them out of the way when attacking with its jaws--both of us assuming that small is beautiful for the creatures.

But, of course, why have any arms left at all?

This fluffy peice claims that T-rex hatchlings had longer arms in proportion to their bodies than adults did. I'm still looking for details. These images show a bit more fragmentation that I'd like--maybe the juvenile was just related to T-rex.

If baby T-rexes had different proportions, presumably their arms were more useful to them than to adults. Tails on a little one wouldn't be as good for weapons as those on an adult, and their bites wouldn't be as incapacitating. Maybe they needed to grapple with the smaller prey to keep it around long enough to finish off. As they got bigger and either faced deadlier reprisals (my notion) or careless co-feasters (Padian's notion), the arms just wouldn't grow as fast, and be vestigial wrt its youth, not wrt its ancestors.

"Tiny tots of either sex Adore Tyrannosaurus Rex Indeed, all little ones adore Any savage carnivore Of which, O Rex, though rightly boastest Thou art not only first, but mostest." ~ Ogden Nash

UPDATE: wrt my notion of keeping fragile parts away from angry prey--a modern comparison : "Most experienced wolves have broken (and healed) their ribs on several occasions." I gather that a number of T-Rex's also have had broken ribs.