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.

Mutant Blastoid Fossil

This unique Pentremites sp. blastoid fossil was found in the Indian Springs Formation of Crawford County, Indiana, USA. It is unique because instead of having five ambulacra (food gathering sections populated with hair like brachioles), this specimen only had three. It is about 1 cm long so it was able to function with fewer sections and grow to this respectable size. Why it mutated would be a good question to get an answer to.

I did not look to see how many holes were at the top of it. If there were only three holes and more of these creatures existed it could be called a Tritremites sp.

This animal lived in the Mississippian Period.

Thanks to Mark for showing me this fossil.

Cleaned Eucalyptocrinus Crinoid Calyx

This crinoid calyx was recently cleaned using a sand abrasive technique. The cleaning revealed a small holdfast at the base of the crinoid cup. I would interpret this as the crinoid cup had broken away from the stem and turned upside down on the sea floor. It had beent there awhile as small holdfasts including one shown below began attaching themselves to the cup. It appears to have been at least 7 crinoid or byrozoan holdfasts. Two near the cup base of the stem might be small Eucalyptocrinus holdfasts. Since the holdfasts were small the fossil got buried pretty quickly thus causing everything to fossilize.

The details show up better when the fossil is wet so I might polish it for better visualization of the plates.

The fossil cup was found in the Waldron Shale of Cheatham County, Tennessee, USA sometime in the 1960s. It was identifed as a Silurian Period Eucalyptocrinus magnus.

Thanks to Kenny for letting me use the cleaning equipment.