Harpacodus Pentalodont Fossil Tooth

Here are some images of the Harpacodus dentatus? petalodont fossil tooth. It was found in the Big Clifty Formation of the Indiana Springs Shale Member of Crawford County, Indiana, USA. The creature existed in the Mississippian Period.

See another example of one at the Indiana State Museum web site HERE.

Thanks to Mark for showing me this fossil.

Ruby Red Shark Tooth Fossil

This is an interesting color for a fossil... ruby red. The following are images of the Thrinacodus sp shark fossil tooth. Thrinacodus was named by Susan Turner in 1982 and this genus is known for its three hook like cusps. It was found in the Big Clifty Formation of the Indiana Springs Shale Member of Crawford County, Indiana, USA. The creature existed in the Mississippian Period.

Why is this fossil so red? Iron content maybe?

Thanks to Mark for showing me this fossil.