Poison Ridge Thunderegg

This site is located in the Owyhee Mountains and was named Poison Ridge because of the large number of rattlesnakes in the area. This inage was provided by the discoverer of the site, who says that this was the only specimen he found that actually had a core. Does this mean that this is a true one off (so far)?

3.5 inches long

Image provided by Jason of Idaho Rockhounding