dino biomass question

[Sam Girouard <sampgir@premier1.net>]

        I'm interested in the relationship between the number of specimens of
groups of dinosaurs vs. their actual percent of the dinosaur biomass of
their immediate area. EXAMPLE: Let's say that at a certain fossil locality,
15% of skeletal remains recovered pertain to ornithomimids, and 5% are from
tyrannosaurids. What would the % biomass for ornithomimids and
tyrannosaurids of the entire dinosaur fauna be? Here are some
considerations that I can think of; (1. Tyrannosaur bone is more dense than
ornithomimid bone, therefore it erodes more slowly and is more likely to be
found and collected; (2. Tyrannosaurs are many times larger than
ornithomimids, therefor tyrannosaur bones are more likely to be spotted in
the field and collected; (3. Tyrannosaurs simply weigh more, so that their
biomass % would needed to be weighted in order to acknowledge this.
        I'm rather confused by the situation, does anyone care to comment or 
offer
some leads?

Thanks,

Sam Girouard
http://www.premier1.net/~samgir/