AW: Number of valid dinosaur genera

["Mallison, Heinrich" <Heinrich.Mallison@mfn-berlin.de>]

Genera are necessarily artificial constructions. So their number means nothing.
:)
HM

-----Ursprüngliche Nachricht-----
Von: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] Im Auftrag von 
dinosaurtom2015@seznam.cz
Gesendet: Freitag, 9. Januar 2015 14:19
An: dinosaur@usc.edu
Betreff: Number of valid dinosaur genera

Good day!

I would like to ask, if there is any comprehensive, up-to-date database of all 
valid dinosar genera, known today (as of January 2015). I seem to recall there 
was about 800 scientifically/taxonomically valid genera and just over
1000 species alltogether. Does anyone run some kind of database from which one 
can directly obtain statistics like how many dinosaur genera are known per 
stage/period, how many saurischians v. ornithischians, how many per 
country/continent etc?

Also, how many dinosaur genera include more than one species? I know that _ 
Psittacosaurus_ is e "record holder" with about 10 species, but what about the 
second and third place? And finally - is there any indication, that _ 
Tyrannosaurus_ had more than one species (i. e. "rex") when we take into 
account that it lived about 2-3 million years on an area spanning from Canada 
to New Mexico? Thank you very much, Tom