Name:
Sphenodiscus lenticularis Age: Cretaceous Formation: Fox Hills Formation Location: South Dakota Size: Ammonite is 2.2 inches across This specimen is not for sale Click here for similar specimens that are for sale
This is a very nice US ammonite. It is a Sphenodiscus lenticularis from the Late Cretaceous of South Dakota. This type of ammonite is extremely lenticular in shape. The planispiral shell of the cephalopod has a very sharp keel. This 3-dimensional ammonite is well preserved and the intricate suture pattern is readily seen. The natural coloration of the fossil is quite striking and contrasts beautifully with the grayish-brown matrix. The ammonite is wonderfully presented on the large, natural block of concretionary matrix that also contains many other fossils. This is a fine example of this unusual ammonite from the Fox Hills Formation.