Cambrian Agnostid Peronopsis interstrictus fossil slab
Middle Cambrian
Wheeler Shale
Millard County
Antelope Springs  House Range
Utah
USA
 
The Wheeler Shale (named by Charles Walcott) is a Cambrian (c. 507 Ma) fossil locality where you can find agnostid , Elrathia kingii trilobite and otehr very interesting trilobites. It is a very good representative Cambrian Fossil-Lagerstätten. In These layers you can find soft bodied organisms  (including Naraoia, Wiwaxia and Hallucigenia).