Nest-depth phylogenetic bracket?

[John Bois <jbois@umd5.umd.edu>]

I'm looking at a cladogram on the inside cover of _Encyclopedia of
Dinosaurs_.  I notice that the only species of non-avian dinosaurs whose
depth is known (Oviraptor and Troodon both lay on the surface) are on
separate branches.  Can a phylogenetic bracketting argument be put forward
about the nesting habits of other species above and below them on those
branches (including _T. rex_)?