Salterella rugosa

• Salterella was a small animal with a pointed conical shell made of calcium carbonate.

• The shell is partially filled with layers of tiny grains of sediments.

• These animals are so different that they have been placed in their own phylum, Agmata, along with one other similar genera.

• These small, shelly fossils are geographically widespread, but mostly restricted to Cambrian sediments, with one report from Ordovician deposits.

• They are abundant in places, sometimes making up half the volume of the rocks.

• It is not known how they fed, but they may have filtered particles from the water.

• This fossil is from the Pioche Shale in Nevada.