Family
Ptychagnostidae Burgess
Shale, Stephen Formation, BC, Canada |
Family
Ptychagnostidae Marjum
Formation, Millard County, Utah |
Family
Weymouthidae Flinders
Ranges, South Australia |
Order
Agnostida Marjum
Formation, Utah |
Family
Ptychagnostidae Marjum
Formation, Millard County, Utah |
Family
Ptychagnostidae Burgess
Shale, Stephen Formation, BC, Canada |
Family
Ptychagnostidae Lower
Wheeler Formation, Utah |
Families Ptychagnostidae & Spinagnostidae Marjum Formation, Millard County,
Utah |