Chuck, non of the native species have antlers or tusks (not even drop bears!) they come from introduced (and now considered pest) species. This tine came off a youngish fallow deer, unfortunately they tend to have thinnish antlers with large palms and lots of smallish tines, so it's difficult to get a lot of material that's useable as knife handles. The palms look really nice but so far I haven't figured out a use for them (too thin).
There are several species of deer across Australia, I just take what I'm offered. I did have some off a Rusa or Sambar that was nice and thick but I used it up making grips for my revolvers.
And yes, I've got to work on the blade a bit, this was in way of an experiment so I'll play around with it a bit - when it gets cooler, it's supposed to be 42*C today!!!!!