Re: Burpee Conference

["T. Michael Keesey" <keesey@gmail.com>]

On 9/20/05, Phil Bigelow <bigelowp@juno.com> wrote:
> 
> The big question is, if "Nanotyrannus" is a juvenile of some other taxon,
> then why haven't we discovered any of its adults in the Hell Creek
> Formation?  The H.C. Fm is one of the most "combed-over" formations in
> the U.S. (as well as the world).  It has been picked over for over a
> hundred years.

Perhaps they *have* been discovered. What are the proposed differences
between _Nanotyrannus lancensis_ and _Tyrannosaurus rex_, and how many
adult fossils currently assigned to _T. rex_ are ambiguous for those
characters? How many specimens currently considered _T. rex_ are
actually _Tyrannosaurini_ incertae sedis?

Another possibility (although very speculative and difficult to back
up): what if _N. lancensis_ was primarily a woodlands or highlands
animal? (That might explain the smaller size ... or is it smaller? I'm
not clear on that.) Maybe very few ventured into areas where they were
likely to be preserved, and most that did were inexperienced
juveniles.

—Mike Keesey