Name:
Placenticeras intercalare Age: Cretaceous Formation: Pierre Shale Location: South Dakota Size: Ammonite is 5.5 inches across. This specimen is not for sale Click here for similar specimens that are for sale
This is a wonderful specimen of Placenticeras intercalare from the Cretaceous of South Dakota. The large ammonite has been extracted from the surrounding matrix so that both sides of the cephalopod can be seen. The ammonite has been polished on both sides to display the intricate suture pattern. The reverse side is just as nice as the side that is pictured. The inner whorls are well defined on both sides. This species is much more ornamented than P. meeki. There are two rows of well-defined tubercles on the flanks with low, rounded ribs connecting these tubercles. Also, this species is much thicker than P. meeki. This is a large specimen of a highly sought-after ammonite from the United States. It just happens to be beautiful, also.