On a recent hike in the San Pedro Riparian area, I found a single example of this plant. That seed pod was about an inch in diameter with spikes all around. Pretty sure those spikes will deter most any hungry critter.
The plants leaves had died so the identification was made on the seed pod. After internet research the plant appears to be in the Datura family which includes the Jimson Weed -- a member of the nightshade family. Reading the varying plant descriptions, I concluded that it was a Long Spined Desert Thorn-apple.
My curiosity wasn't enough to combat those spines. Probably a good thing considering that the plant is highly poisonous.
Those spines were a clear message, "Leave me alone."