I can’t really speak much in the regulations in Queensland as I don’t know much about them but can say that Tasmania would be giving them a good run for their money!
For any species not currently in Tasmania a species risk assessment has be undertaken before a species can be allowed in (note that this is different to federal IRAs). The species is then assessed based on its potential to establish itself in the wild in Tasmania and the potential risk it then poses to Tasmanian wildlife and agriculture, the species is then allowed or prohibited, and in some cases restrictions are put in place. These are also put up for public comment and are open to criticism, which has in the past caused a lot of trouble, with the local farmers association fighting back wanting African Wild Dogs prohibited in case the escape and interbreed with domestic dogs (which isn’t possible). As a result the species can only be held in non breeding groups.
It’s worth noting as well that the majority of these risk assessments have been put through by Tasmania Zoo, who have to develop a species profile and proposed pros and cons for the species before the local authorities will assess it, all of which costs time and money.
Working with similar species that are already held makes it a lot easier, ie similar primates are already held and approved and have low risk of survival in Tasmania so are a better chance of being approved. However the opposite is also true in that deer have already established and built wild populations in Tasmania and are prohibited from importing, as are Himalayan Tahr (as a result of wild populations in NZ). Bison have recently been approved but I believe only male/nonbreeding groups. In this case it makes it harder for zoos to warrant putting months of staff time into a document only to get knocked back. Addax have been approved but never imported by any zoos to my knowledge so may be some restrictions in place that have deterred zoos acquiring them. That’s not to say Tasmania Zoo won’t look at some of these in the future but this, along with difficulties in the transport logistics of moving these animals across the bass strait, would probably offer some reason for the lower number of ungulates in the collection.
As a side note too that might be of interest, there are a number of Australian native species that are prohibited, including macropods, dingos and birds, as a result of the risk levels of escaped. There were previous Agile wallabies held at wildlife park down here and there is now a wild population of escaped animals established around Bicheno.
Here’s a link to a list of approved species of it’s of interest to anyone:
Species Risk Assessments | Department of Natural Resources and Environment Tasmania