Monday, May 27, 2013

Waldron Shale Scolecodont Fragment

This picture is of a microfossil called a scolecondont (part of a worm jaw). It was found in the Waldron Shale of Clark County, Indiana, USA. The age is around 420 million years old which would place it in the Silurian Period.

It reminds me of a Silurian scolecodont found in Sweden called Kettnerites sp.  Also one found in New York called Nereidavus invisibilis. I have not been able to find much research on the ones found in the American Waldron Shale though.

Thanks to Kenny for the picture.

Monday, May 13, 2013

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.

Sunday, May 12, 2013

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.

Thursday, May 9, 2013

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.

Tuesday, May 7, 2013

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.

Monday, May 6, 2013

Cleaned Silurian Trimerus Trilobite

This Trimerus delphinocephalus (Green, 1832) trilobite has been prepped using a dental tool and toothbrush. This particular picture has been touched up with Adobe Photoshop to fill in the missing areas of the fossil. Most of the work was done to the front scoop on the cephalon and the sides of the pygidium (tail). Also cracks in the thorax plates and areas where the eyes were placed are covered in brown.

Fossil was found in the Waldron Shale of Clark County, Indiana, USA. It dates to about 419 million years ago which is the Silurian Period.

This next image is a close up of the thorax segments on the side of the fossil. The detail of the texture on the plates is nice. A series of small bumps can be seen, maybe these served as some sort sensory system.

This last series of pictures show the fossil from different angles. Thanks to Kenny for prepping this fossil!

Sunday, May 5, 2013

Strophodonta Brachiopod from Wisconsin

This is an updated posting of a fossil I have already listed. It is a Strophodonta brachiopod fossil found in the Milwaukee Formation of Wisconsin. It is from the Middle Devonian Period.

The fossil has now been cleaned to reveal more of its detail including a coral colony (possibly some sort of Aulopora). The matrix was a little stubborn and it took some time to remove it. I think the canister was refilled three times before I finished working on it. Some the fossil may have been removed by me exposing the surface too long to the sand stream. As you can see from the image below the matrix is a light gray while the fossil is a dark blue-gray color.

Here are some close up images of the coral colony. They were photographed wet since it tends to reveal more of the coral detail.

Thanks to Nathan for this fossil and Kenny for letting me use his sand blasting apparatus.