nobiliasaphus delessei trilobite. ordovician period

animal animals appalachian appearance arthropoda asaphid batch compressed dark delessei embedded evolution extremadura fauna fossil fossils geological geopark geosite geoturism ghostly global heritage history marine metamorphism mineralized mudrocks nobiliasaphus ordovician paleontology prehistorical pygidial records regional silty slate small spine trilobita unesco villuercasiboresjara