Wednesday, April 17, 2013

Almost Complete Silurian Trimerus Trilobite

These pictures show an almost complete Trimerus delphinocephalus trilobite. It was fossilized intact but was found in two pieces. Some of the last thorax segments and the pygidium (tail) had broken off this specimen. It is still missing part of its feeding/digging scoop and small pieces of segments missing from the rear section of the trilobite. Visually it appears to be about 95% complete.

After some effort, I was able to find the broken off tail section of this trilobite. It was not too damaged and fit  right into place on the original piece found. Whew! I gave an early birthday present to myself. :)

Fossil was found in Clark County, Indiana in the Silurian age Waldron Shale. It has not been cleaned and two parts of it have glued back together. I hope once it has been abrasive cleaned extra matrix and glue will be removed.

Compare it to another Clark County Trimerus trilobite fossil found on the Internet at this web site: Week's trilobite web site.


Tony Edger said...

Fantastic fossil and in such great condition. I am amazed that it hasn't been cleaned yet. Anything special about how you found it?

Kentuckiana Mike said...

It is a great find! The fossil preservation is really good when it comes to the Waldron Shale. It does decompose quickly once exposed to the elements.
I only saw a small 1 cm size piece of this fossil uncovered and when I dug it out it was covered in gray mud. The thorax ridges could be made out even without the brown color showing. The tail piece was found about 30 cm away buried about 5 cm down which took a while to find. :)

Dave said...

Impressive find Mike! I really like how it isn't in a static position and instead looks like it was hunting.