One each of Knightia small size. (No. 16) Wyoming's state fossil. Knightia are members of the family that includes modern herring. Eocene in age, dating back approximately 40-60 million years,and found in sedimentary rock in a prehistoric freshwater lake, now known as Fossil Lake in the Green River Formation. The stated size of small relates to the size of the fossil fish which are nicely cleaned and prepared on the cream colored limestone matrix. The fish are approx. 3" in length, but overall size of the matrix surrounding the fish may vary from some sized at 2 3/4" X 6". Knightia was named after Wyoming's first state geologist, Wilbur Clinton Knight and became the state fossil in 1987.