Black-headed Strobe Ant

This large individual was found in a sandy wetland habitat. The only picture record I found was Opisthopsis queen (see https://lifeunseen.smugmug.com/Insects/Ants-order-Hymenoptera/Subfamily-Formicinae/Opisthopsis/i-4VXzrcT). Bowerbird has another picture of a very similar animal which however has wings. The animal was crawling fast, hardly ever stopped and ignored me and my pocket camera. Being solitary, I thought it was a sort of a ground wasp, but am confident that it is an ant. It could actually cause the sand circles, obviously the home of big ants, often observed nearby.