fieldmuseumphotoarchives:Fossil Friday, Gastropod.© The Field Museum, GEO81096.Silurian gastropod. T
fieldmuseumphotoarchives:Fossil Friday, Gastropod.© The Field Museum, GEO81096.Silurian gastropod. Thornton, Illinois. Fossil invertebrate.4x5 cellulose acetate negative5/23/1952 -- source link