Tuesday, October 6, 2009

Devonian Period Phacops Trilobite

The following are some trilobite fossil pictures taken using a glass plate to eliminate shadow. The lighting could be better and my background cloth is a little wrinkled. I did not set up the light box but instead used a much more primitive setup.

The fossils were found in Clark County, Indiana. They are from the Devonian Period.

This first three images are of the same fossil. It is one of the better specimens I found that day. The Phacops rana trilobite is a little over 2 cm wide. It is possible the whole trilobite is intact. The pygidium and lower thorax are partially covered by matrix. I will try air abrasion cleaning at a later date. Unfortunately, the compound lens of the trilobites eye are gone from one side. I count 8 thorax segments visible.

Welcome to the land of fossils in Clark County, Indiana. This rock layer might be Jeffersonville Limestone. Beautiful day to collect!

Phacops rana cephalon that is probably a molt. Two views of the same fossil.

Fragment of a Phacops rana cephalon that seems to have a bit of black maganese on it.

Upside down cephalon embedded in matrix. This trilobite is probably a Phacops rana.

Insect Fossils from the Carboniferous

The following insect fossils are on display in Paris, France at the Muséum National D'Historie Naturelle Jardin Des Plantes Paléontologie et Anatomie Comparée. Note, I have changed the contrast on a lot of these fossil images to make the fossil standout from the rock matrix.

UPDATED: I would like to thank Dr. Sam Heads, a paleoentomologist at the Illinois Natural History Survey, for providing detailed comments about the images on this post. His observations are in quotes throughout this posting. Find out more about Dr. Heads research at this site: http://myprofile.cos.com/swheads

I believe all these insect fossils are from the Carboniferous Period. This insect fossil looks like some sort of dragonfly. It was called Isophlebia aspasia.

"Isophlebia aspasia (Hagen, 1862) is a dragonfly (order
Odonata) of the family Isophlebiidae. This specimen is from the
Late Jurassic Solnhofen Limestone of Bavaria, Germany."

This next one looks like a water skater. It is called Pygolampis gigantea and is probably from Germany.

"Pygolampis gigantea Germar, 1839 is now known to be a
junior synonym of Chresmoda obscura Germar, 1839. These
insects belong in the unusual extinct family Chresmodidae; a
polyneopterous group which may be related to the stick insects
(order Phasmatodea). This specimen is also from the Late
Jurassic of Solnhofen."

These last two pictures are of the Meganeura monyi found in Allier, France. NOTE: I was getting some major reflections from the posters hanging on the walls on the case glass when taking some of these pictures. Ahhh!

"Meganeura monyi (Brogniart, 1893) is one of the giant
members of the Paleozoic order Protodonata (or 'griffenflies') and
belongs in the family Meganeuridae. This specimen is from the
famous Carboniferous (Stephanian) coal measures of
Commentry, Allier, France."