Hi Kevin, this ant could be Myrmecia forficata, but I can't really tell from the photo. Myrmecia forficata seems to normally to have a brownish body and head with black gaster (rear end; see images at the Atlas of Living Australia website) so this ant would be unusually dark for this species. But I can't be sure what species it is from the photo, so have just confirmed your ID at genus level. Cheers, Jon
Thanks Jon This ant was much larger than 12mm, closer to or greater than 25mm, larger than the range quoted in Wikipedia for the Jack Jumper but I will be guided by your advice.
Hi Kevin, just to clarify, identifying the ant as "Myrmecia sp (genus)" just means that we are sure that it is an ant in the group (genus) called Myrmecia, but we can't be sure what species it is. Which means it could be any of a number of large bulldog ants, which can be very big, as you say. Cheers, Jon