Ptychagnostus atavaus (Tullberg, 1880) Dataset GBIF Backbone Taxonomy Rank SPECIES Classification kingdom Animalia phylum Arthropoda class Trilobita order Agnostida family Ptychagnostidae genus Ptychagnostus species Ptychagnostus atavus Name Homonyms Ptychagnostus atavaus (Tullberg, 1880)