Cretaceous Clam Fossil

While touring the Natural History section of the Arizona Historical Society Museum at Papago Park (1300 N. College Ave, Tempe Arizona 85281) I saw this clam fossil specimen (AHS-NH#21712)

This fossil was probably found in the Pierre Shale Formation of Glendive, Dawson County, Montana, USA. It dates to the Cretaceous Period.

Image was taken in October 2014.

Sources:
Neat image of Cretaceous Inoceramus clam fossil with pearls
http://www.paleocurrents.com/baculite_mesa/img/2003-05-17mesa_fossils/HTML/img_2480.htm

Harpes perradiatus Trilobite Fossil

Image of  a Harpes perradiatus trilobite fossil. This creature existed in the Middle Devonain Period.

While visiting the Gallery of Natural History at the Arizona Historical Society Museum at Papago Park (1300 N. College Ave, Tempe Arizona 85281) I saw this fossil specimen (AHS-NH#20671).

It was found in what is now Alnif, Morocco, North Africa.

Images of museum specimen taken October 2014.

Source to refer to:
http://www.fossilmuseum.net/Fossil_Galleries/TrilobitesMorocco/Harpes-perradiatus/Harpes.htm

http://en.wikipedia.org/wiki/Harpetida

Fossil Shark Teeth of South Dakota

My cousin recently received some matrix from the Carlile Shale Formation of Grant County, South Dakota, USA. He has been carefully breaking it down to extract the hidden fossil shark teeth.  The fossils date to the Cretaceous Period (Turonian). We have been trying to identify what they are. So far names I am considering are Leptostyrax, Cretalamna (Otodus), and Cretodus.

Thanks to Kenny for images.

Info Sources:
http://www.thefossilforum.com/index.php?/topic/41692-south-dakota-matrixteethclaws/

http://oceansofkansas.com/KS-sharks.html