Progress on Calymene

Over 400 million years ago, the muddy seafloor stirred below a deep tropical sea.  Slowly, the armored headplate of a multi-segmented creature emerged from the muck.  Today the fossilized remains of that creature is slowly emerging from its stony grave... behold the Calymene trilobite.

Yesterday, the matrix with this fossil was profiled today more of the remains are revealed.  Using a dissecting needle, toothbrush, water, and gentle prodding the matrix is slowly being removed to expose more thorax and cephalon detail.  The pygidium is hanging over the matrix so pressure applied there could snap it off.  That section will need to be abrasive cleaned.  Trilobite is a little over 5 cm long.

Here is a close up of the cephalon section.

Calymene Challenge

It appears this is a complete Calymene trilobite of the Middle Silurian Period.  It is about 5 cm long and will be a challenge to coax out the matrix.

Catch a Trimerus by the Tail

The Trimerus delphinocephalus (Green, 1832) trilobite of the Silurian Period. This first image is from a 1910 book. The picture is to give you an idea of what the entire trilobite looked like. Today's highlighted fossil is just a fragment of one of these trilobites (the rear section or pygidium).

Trimerus delphinocephalus (Green, 1832)

North American Index Fossils by Amadeus Grabau & Hervey Shimer

Volume II, 1910

Trilobite found in Niagaran of New York, Ontario, & Indiana

Image from page 317

This is a beautiful fossil fragment just recently found in the Waldron Shale of Clark County, Indiana.  Select the image to see a larger version and note the detail still left on the fossilized outer shell.  It has such a beautiful color.  Preservation is such that one can run their finger over the shell and feel the bump/segment details. The fossil needs a little work with an engraver and sand blasting of little bits of matrix.

See an intact one on the Dry Dredgers web site found in New York.

Thanks to Kenny for letting me photograph this fossil.