Fossil sperm whale teeth

This post concerns a recent trip by one of my colleagues who found a concretion containing two fossil sperm-whale teeth. Each tooth appears to be split in half and is not the half of the other tooth. The one on the right is upside down because the top of a sperm-whale tooth is commonly tapered. The teeth are of Miocene age and from southern California. In my own collecting experience, fossil sperm-whale teeth are rare finds.

Miocene sperm-whale teeth (half sections) from southern California.
 The tooth on the right is 7 cm in height and 3 cm in width.