Most of my attempts to illicit strike responses from turret spiders end in failure, but for whatever reason Trent was able to get this one to cooperate. I tried to reciprocate but again without luck. Trent was gently stroking the edge of the turret with a twig, whereas I was poking it, so maybe the key is to immitate a smaller insect. There's anecdotal evidence to suggest that they eat ants, so maybe think ant-sized movements. Also, you need to do it under cover of full darkness for them to be staged near the burrow entrance (though they seemed willing to strike under flashlight illumination).
Note the deep, transverse foveal groove and the sclerite on the abdomen, both indicative of the former genus Atypoides (Adams 2014).
Defensive posture. You can see some of its milky secretions on its tail, which are supposedly noxious. Wonder what chemicals are used...
There were a couple of big ones at this location, mostly in crevices, most looking reasonably healthy.
Sam, what's going on here other than this? I'll answer my own question: gonopods.