Monday, November 30, 2009

Ptychodus Shark Crusher Teeth

A Hybodotid shark crusher teeth called Ptychodus whipplei. These crusher teeth were used eat shell fish. The fossil was found in the Upper Cretaceous Period (about 70 million years ago). It was found in Dallas County, Texas in the Kamp Ranch Formation.

Thanks to Herb for the images.

Sunday, November 29, 2009

Shark Protolamna sokolovi

A late Cretaceous Period (about 112 million years ago) fossil tooth of the Protolamna sokolovi shark. This fossil is from the rare Lamnid shark. It was found in the Paw Paw Formation found in Tarrant County, Texas.

Crowns feature deep longitudinal grooves at the base.

Thanks to Herb for the image.

Saturday, November 28, 2009

Mortoniceras Ammonite Fossil

The distinctive ribbed coiled ammonite is known as the Mortoniceras sp. found in Tarrant County, Texas. It was found in Duck Creek Formation and the creature existed in Upper Cretaceous Period (Albian Stage; approximately 100 million years ago).

Thanks to Herb for allowing me to photograph this specimen.

Friday, November 27, 2009

Bryozoan Holdfasts

This entry shows a number of Ordovician Period bryozoan holdfasts. They were found in Franklin County, Kentucky in the Lexington Limestone.

Thanks to Kenny for the images.

Thursday, November 26, 2009

Phacops Trilobite From Ohio

This trilobite is from Lucas County, Ohio. This trilobite is probably my favorite because it is the one I find the most in the Louisville, Kentucky area. The creature lived in the Paleozoic Era in the Middle Devonian Period (around 395 million years ago).

This one was probably found in Silica Shale. It is from the phylum Arthropoda and was called Phacops rana (I have also seen specimens from Ohio referred to as Phacops rana crassituberculata). This trilobite might also be known by the name Eldredgeops rana. The fossil trilobite must be found quite a bit in Pennsylvania was well since it is their state fossil.

This specimen is enrolled sort of like the modern day isopod Armadillidium ("pill bug") does. Also note the large compound lens eyes. This type of eye is called Schizochroal allowing the trilobite to have 360 degree vision. Since the creature had this ability I am guessing it was preyed upon by something (maybe a shark).

Thanks to an anonymous friend for the images.

Green River Fossil Fish

This fossil fish was extracted out of the rock by my cousin using just scraping tools. It is from the Green River Formation in Wyoming.

I believe this creature existed in the Eocene period (approximately 55-34 million years ago).

Thanks to Kenny for these images.

Another fossil fish that is a work in progress and slowly emerging from the rock matrix.

Wednesday, November 25, 2009

Pterotrigonia thoracica Pelecypod

The Pterotrigonia thoracica (Morton 1834) pelecypod is the official state fossil of Tennessee. It existed during the Cretaceous Period (about 70 million years ago - Maastrichtian). This fossil was found in McNairy County, Tennessee (Coon Creek Formation).

It became state fossil in 1998.

This creature might be related to the Myophorella ("Trigonia") of the Jurassic Period which has the modern relative of the Australian Broach Clam (Neotrigonia margaritacea). Learn more at this British website: Fossils of the Kimmeridge Clay (Southern England) by Ian West.

The genus was named by van Hoepen in 1929.

Thanks to Herb for allowing me to photograph it.

Update: August 2010, here is a picture of two Trigonia on display at the Smithsonian Museum of Natural History in Washington, D.C. The ones on the top are Trigonia thoracica (Late Cretaceous Period, Tennessee) and the bottom one is Trigonia moorei (Middle Jurassic Period, Australia).

Brevispirifer gregarius Brachiopod

It has taken a while to find an intact specimen of this brachiopod. It has special significance in the Louisville area. The fossil marks a zone of the Jeffersonville Limestone. The small book entitled Middle Devonian Type Jeffersonville Limestone at the Falls of the Ohio by James E. Conkin, Barbara Conkin, and Larry Steinrock refers to this fossil quite a bit. The book and the Internet do not have good images for identification. Recently, I was lucky to find several complete ones. In the past, I have found the shells in rock plates, just one half, or fragments.

These specimens were found in Jeffersonville Limestone and existed in the Middle Devonian Period.

This brachiopod is known as the Brevispirifer gregarius and the ones in this picture range in size of 1-1.5 cm wide, 1-2 cm tall. It was named by Clapp in 1857 as Spirifera gregaria. The brachiopod is also found in Ohio in the Columbus Limestone.

Now that I have found some good specimens, I need to get a good photo of the Devonian Period horn coral Bordenia knappi.

Tuesday, November 24, 2009

Hemiaster whitei Fossil

A Hemiaster whitei sea urchin fossil found in Tarrant County, Texas. Goodland Formation was the location this fossil was located. The creature existed in the Lower Cretaceous Period (about 105 million years ago).

Thanks to Herb for the image.

Kentucky Star Fish Fossil

Here is a star fish or sea star fossil found on a field trip to Franklin County, Kentucky. It is a very rare find. The fossil was found in the Lexington Limestone and dates back to the Ordovician Period.

The Fossils of Ohio book shows one called Salteraster grandis (Meek).

Thanks to Kenny for the image.

Modern day star fish for comparison.  I believe the star fish was found in Florida.



Monday, November 23, 2009

Cornulites on Rafinesquina Brachiopod

Interesting fossils in this picture of a brachiopod shell hosting a number of worm tubes. These fossils are from the Ordovician Period and were found in the Lexington Limestone(?) in Franklin County, Kentucky.

There appear to be 15 worm tubes (Cornulites) on the Rafinesquina brachiopod shell. Apparently the brachiopod was dead when the five attached themselves to the inside of the shell.

Approximately 10 Cornulites attached to the outside of the shell.

View of five worm tubes attached to inside of the shell.

Closeup of the shell edge with worm tubes.

Sunday, November 22, 2009

Part of a Carpoid?

This fossil remnant is the most interesting find I had from a field trip to Franklin County, Kentucky (about 55 miles or 88 km east of Louisville, Kentucky). I think it was found in the Lexington Limestone and is from the Ordovician Period.

It might be part of a carpoid. It also could be part of crinoid calyx. Either way this seems to be a pretty rare fossil for the Ordovician Period layer I was looking at. The plate segments somewhat remind me of a turtle shell.

The fossil fragment is in a larger rock that contains Isotelus trilobite pieces, small branching bryozoa, some type of spiral gastropod, and pea size brachiopods.

Learn more about carpoids found in Ordovician rock at the Dry Dredgers website.

UPDATED:  Dr. Colin Sumrall from the Department of Earth and Planetary Sciences at The University of Tennessee Knoxville identification of this fossil fragment as a rare carpoid Stylophoran Enoploura.  Learn more about carpoids at this website.  A big thank you to Dr. Sumrall for taking time to look at the fossil images!

Saturday, November 21, 2009

Aulacophyllum Horn Coral

Aulacophyllum horn coral found in the Jeffersonville Limestone of Clark County, Indiana. The coral grew in the Devonian Period.