Fossilized Algae Margaretia dorusExcellent example of an authentic fossilized algae specimen Margaretia dorus. Age: Middle Cambrian (521 to 497 mya) Species Name: Margaretia dorus Locality: Wheeler Shale, Millard County, Utah Size: Approximately 7" x 8" shale piece with a 3 1 2" x 7 8" specimen. Comes with stand Most collected Margaretia are not this detailed and have an orange red coloration due to high iron content which most often causes a lack of clear distinct patterning as in