original description
Gabb, W. M. (1866-1869). Geological Survey of California. Palaeontology. Volume II. Cretaceous and Tertiary fossils. <em>Palaeontology. Volume II.</em> 1-38, pls. 1-13 [Feb 1866]; 39-299, pls. 14-36 [1869?]; i-xiv [1869]., available online at https://www.biodiversitylibrary.org/page/2066671
page(s): 13, pl. 2 fig. 21 [details]
From editor or global species database
Type locality "On Snake River, Idaho Territory, on the road from Fort Boisé to the Owyhee mining country" (now near Walters Ferry, Idaho), USA; Glenns Ferry Formation, Pliocene [details]