nitpicking...

[Torfinn Ørmen <torfinn.ormen@nhm.uio.no>]

>> No, dinosauriorum is correct afaik. Dinosauria is treated as a plural, so
we
>> use the plural genitive ending.
>
>Apparently it is correct, but that depends on whether the singular is
>dinosaurium or dinosaure. :-)
>
>> I had essentially two choices: Dinosaurium
>> Catalogus or Catalogus Dinosauriorum, which translate as Dinosaur
Catalogue
>> and Catalogue of the Dinosaurs, respectively.

The latin nominativ singular is dinosaurus, gender masculine,
root dino-saur-.
The genitive plural would AFAIK be dinosaurorum.
This would give Catalogus Dinosaurorum "Catalogue of the dinosaurs".

The alternative is to use the group name Dinosauria, which would either be
1) a plural of a neuter "Dinosaurium" (to me this sounds like a name for a 
room
with dinosaurs, like librarium "book room", laboratorium "work room", etc,
so I don't think so -but it would be a swell name for a dino museum...),
or
2) a feminine singular (it is after all a name for a defined group) which 
gives
the genitive Dinosauriae.
Thus: Catalogus Dinosauriae "Catalogue of the Dinosauria"

The word order depends on which word we want to put the emphasis on.
If we want to stress the dinosaur aspect: "Dinosaurorum catalogus".
(Personally I prefer this alternative.)

-Well, just my suggestions. :-)


Cheers
Torfinn