Otodus obliquus:  Fossil teeth of an extinct type of mackeral shark from the phosphate beds at Khouribga, Morocco.  These teeth are from the Paleocene epoch, about 60 million years old, dating from just after the great Cretaceous extinction event.  Some paleontologists think that Otodus was ancestral to the Miocene epoch apex predator shark Carcharodon megalodon.
The teeth remain embedded in the natural phosphate formation in which they were found.