Cryptolithus Ordovician Trilobite Fragment

This image shows a Cryptolithus tessellatus fragment found years ago.  It existed in the Ordovician Period. The fossil plate was found in the Kope Formation of Carroll County, Kentucky. When cleaning fossils recently, it was in a box waiting to be finished. I will try and air abrasive clean it soon. The question is the tear drop center section intact. My cousin extracted some of the matrix with an air scribe but that area now needs to be excavated with the sand blaster.

The plate this fossil is on has another Cryptolithus with part of the cephalon and an imprint of that center tear shape.

See my previous post about other trilobite fossils found at this locality.

On the back of the plate are a number of graptolites (see picture above - photographed wet). See images from previously found fossils in Carroll County at this blog posting.

Tear Shaped Glabella

This fragment shows a mold and some of the shell replaced by brown calcite of the glabella of a Cryptolithus trilobite.  The fossil was found in the Kope Formation of Carroll County, Kentucky. The trilobite lived in the Ordovician Period.

Cryptolithus Trilobite Information

TIME PERIOD:
Creature existed in the Ordovician Period (about 488 to 443 million years ago) defined by the English geologist Charles Lapworth in 1879 after the Welsh tribe called Ordovices.  This period occurred in the Paleozoic Era (consists of: Cambrian, Ordovician, Silurian, Devonian, Carboniferous (in U.S. Mississippian/Pennsylvanian), and Permian Periods).

CLASSIFICATION:
The taxonomy of the Cryptolithus tessellatus
Domain: Eukaryota
Kingdom: Animalia
Subkingdom: Bilateria
Branch: Protostomia
Phylum: Arthropoda
Class: Trilobita
Order: Asaphida
Family: Trinucleideae
Genus: Cryptolithus

HABITAT:
I found two papers North American Biogeography and Taxonomy of Cryptolithus(Trilobita, Ordovician) by Fredrick C. Shaw and Pierre J. Lespérance, Journal of Paleontology 68(4), 1994, pp. 808-823 and Viola Group (Ordovician Oklahoma) Cryptolithinid Trilobites: Biogeography and Taxonomy by Fredrick C. Shaw, Journal of Paleontology 65(6), 1991, pp. 919-935 that describe the Cryptolithus in more scientific detail.


They describe the habitat as being water of at least 30 meters (approximately 98 feet) in depth with muddy sediment.  The trilobite was thought to be blind and a bottom feeder.  In addition, it was isolated for millions of years in a cool water shelf like environment.

The Cryptolithus (Green, 1832) trilobite remains I find east of the Louisville, Kentucky area are in what is called the Kope Formation.  I find small brachiopods, cepholopods, and crinoid stems with the Cryptolithus fossils.

One might also check out the website: www.trilobites.info for more information.

Cryptolithus Trilobite Fragments

These pictures are of Cryptolithus (Green 1832) trilobite fragments found east of Louisville, Kentucky USA. They are found in the Kope Formation and from the Ordovician Period.

Cryptolithus Drawing Version 2

Using Adobe Illustrator and then touching up with Adobe Photoshop I created a second version of yesterday's drawing. The thorax and pygidium have been redrawn. The right side of the lace collar was mirrored and the lines of the outer rim of the cephalon adjusted. Shading was added in an attempt to create depth for the cephalong and glabella.

Cryptolithus Trilobite Diagram

Here is a quick rendition of a Cryptolithus trilobite from the Ordovician Period. I needed to make a label for a fossil I was sending out. I took some artistic license with holes in the lace collar, the deformed glabella, and the warped looking thorax segments. Probably when digitally composing a trilobite, it is a good idea to do either the right or left half and then reflect it along the y-axis.

Ordovician Cryptolithus Trilobite Fragments

These pictures show fragments of the Ordovician Period Cryptolithus trilobite found in Carroll County, Kentucky. It was found in the Kope Formation.


The U shaped collar is visible at both ends but the middle is obscured. I want air abrasive clean this fossil to try and reveal the entire cephalon (if intact). Mystery object in the left top corner could be a starfish arm.


You will need to click to enlarge this picture. This is a rock plate that had one of the previous shown trilobite fragments. Herb from KYANA Geological Society (Louisville, Kentucky) was looking at this piece and pointed out that this could be a starfish arm.

Pennsylvania Cryptolithus Trilobite Fragments

More fossils from Pennsylvania. These trilobite fragments are quite nice. We have places east of Louisville that will yield Cryptolithus pieces but they tend just be the lace collar and genal spines and are black/dark gray. The following fossils have the glabella and the lace collar and are orange (iron?). The cephalon sizes range from 5-15 mm.

These Cryptolithus sp. were found in Lebanon County, Pennsylvania in the Martinsburg formation.

Update: The yellow-brown color is limonite (hydrated iron oxide-hydroxide).

Cryptolithus Trilobite Fragments

Here are some Cryptolithus trilobite fragments from Carroll County, Kentucky.

Cryptolithus Head Plates

Here are several Cryptolithus sp.trilobite remains found in Carroll County, Kentucky. One still has part of its side spine intact. I have wondered what purpose this spine serves being so close to the body and swept back along the side. Is it possible the trilobite propelled itself backwards with its tail like crayfish do today? As if sped backwards this two spines would protect it if it hit something like a rock or hostile creature?

I also wonder about all the holes along the creatures front rim. Are these some sort of sensory mechanism? I have read this creature is blind so it either navigated with antenna or maybe used this hole system as some sort of detection grid. Of course if it lived in a dark environment, eyes are not really that useful.

This creature lived in the Ordovician period and is in the company of remains from bryozoans and crinoid stems.

Cryptolithus Trilobite

Here a Cryptolithus trilobite from the Orodovician time period (438-505 million years ago). It was found in Carroll County, Kentucky. It is part of the head plate (cephalon) with a spine attached.