This  Collignoniceras woollgari  juvenile ammonite fossil is on display at the Mesa Verde National Park as of August 2014. The ammonite e...

This  Prionocyclus macombi  (Meek, 1876) ammonite fossil is on display at the Mesa Verde National Park as of August 2014. The ammonite exi...

A colleague of mine recently returned from a vacation to Montana.When he was showing me pictures from his trip I found the one shown in t...