| Top and bottom--Ammonoids from the middle to upper Mississippian Chainman Shale, White Pine County, Nevada. Specimens--Top: 1 to 3--Cravenoceras nevadense; 4 to 16--Cravenoceras hesperium; 17, 18--Cravenoceras nevadense. Bottom: 4 and 5--Goniatites choclawensis; 9 to 12--Cravenoceras merriami. Photographs courtesy Walter Youngquist; I edited and processed the images through photoshop. |