This is a very interesting fossil. It is a rare Hyolithes sp. from the Weeks Formation of Utah. This organism has remained an enigma since the beginning of modern scientific description. Authorities are unsure of where it belongs in a classification of the invertebrates. It may be related to mollusks but in a separate phylum. This specimen is simply huge! The conical shape of the organism is beautifully displayed, and the textured pattern is quite evident. The fossil has good color and contrast and is almost perfectly centered on the rectangular plate of limestone. This is an excellent example of this problematic fossil.