[dinosaur] Non-avian dinosaur biodiversity

[Poekilopleuron <dinosaurtom2015@seznam.cz>]

Good day to all listmembers! I wonder, what was the true biodiversity of 
non-avian dinosaurs during the Mesozoic? I am aware of some estimates of the 
number of taxa ranging from 1000 to about 6000 species, but it seems far too 
small a number to me. Personally I would have guesstimate on the order of tens 
of thousands species, perhaps even more. At least that is what research in 
microsites, Burmese amber etc. suggests. Any opinions? Thank you in advance! Tom