It would be interesting to know how long it took a TRex to grow from birth to 90% of it's eventual adult weight. A Year? Ten Years? 20 years?
What was the lifespan of a TRex and at what age did they begin to reproduce?
There was a discussion of the Mini-Rex on NPR Science Friday this afternoon (pure chance that I happened to catch it). They were interviewing the scientist who reported this specimen.
Based on bone fusion they were able to determine the age of the mini-individual, and it was a full grown adult at about 10 years old. In comparison, the large T-Rex's were adolescent at 15 and full grown at 20. The T-Rex specimen they named "Sue" was 28 years old and considered geriatric in T-Rex lifetimes.
The scientist also made a pretty good case for this specimen being very close to the ancestral line of T-Rex's, and not something else like an Alosaurus. He talked about the small front limbs in particular and said that some very particular ratio's between the front limb design and other anatomical features made this mini-rex very likely to be very close to the ancestral line of the bigger T-Rex's.
He fielded questions ranging from whether this mini-rex was a juvenile, or possibly an entirely different species exhibiting convergent evolution or whether it might just be a single-occurrence "freak" animal (none of which held up as well as an ancestor). They talked about the strata the fossil was embedded with as well as the formation conditions.
It was a very interesting NPR Science Friday show