Although there have been an abundance of pre-(H)istory plants and animals found in the "New Land", the process of retrieving them and bringing them to the Continent has been slow. The New Land is vast and hard to explore, due to the high density of Magica and the various powerful beasts and monsters that dwell there.
It is amusing to me that we have no need to retrieve cats from the New Land, as they have existed on the Continent During Pre-History, the Golden Age, the Fall, and into Modern times. No matter where you go, cats seem to have found their way there and are living happily.
I have heard rumors, unsubstantiated of course, that they are the only mundane animal that lives and thrives in the Demonic Planes...
-Notations on culture, by (H)istorian Costanza Godhand