Trilobite Cryptolithus tessellatus

The Anatomy of Cryptolithus tessellatus

Cryptolithus tessellatus, better known as the Lace Collar trilobite, is very common in the Edenian Stage of the Cincinnatian Series. Yet it is very rare to find a complete specimen. You are likely to only find fragments. It is very fitting, therefore, that a page is devoted to Lace Collar trilobite fragments. Most often, you will find the "lace collar" parts of these trilobites on the surface of rocks in the Kope Formation (Latonia Formation of Cincinnati, Ohio).
 


A complete Cryptolithus sp.
Photo courtesy of Steve Brown


Commonly Found Fragments of Cryptolithus

 
 

The "lace collar" of the Cryptolithus is it's most commonly found fragment. In fact, it is the only fragment you are likely to find from Cryptolithus. It is abundant in the Southgate member of the Latonia Formation. They can be found loose in the mud or encased in shale. The lace collar is identified by it's round indentations that are lined up in rows along the curve of the trilobite's genal area. The lace collar terminates with a genal spine. 

 

This is the inside of the "lace collar." Instead of indentations, you see raised dots lined up in rows along a curve. The raised dots have a hollow center, as shown at left.

 

The left and right genal area's are often found intact in the shale or limestone matrix. As pictured at left, the glabella, or center, is usually missing and the lace collar is in a "U" shape. 

 

The genal spine, shown left attached to a lace collar, is quite long. It extends beyond the length of the body. The spine pictured here has an indention running its length, although barely visible in the picture.

 

Another example of a genal spine on a lace collar.  In this example, the spine is smooth and round, lacking the indentation in the previous example.

 

Here is an example of lace collars imbedded in a slab of shale. This is a very common way to find lace collars and gives you an easy clue that you are in the Latonia (Kope) Formation. 

 

 

Cryptolithus glabella. The left cheek in this example is missing (bryozoan shows in it's place.) The top of the center glabella is worn down, which is typical of most Cryptolithus glabella specimens.

 

Inverted Cryptolithus glabella. The right cheek in this example is partially missing. The interior view, as shown, is uncommon because the glabella is so fragile.

 

On this Cryptolithus glabella, you can see the occipital spine. This is a spine almost never preserved on specimens and is found protruding from the axial lobe of the glabella. (Click on the thumbnail image to see the occipital spine better.)

Here's more information!

Fragments of Trilobite Isotelus
Fragments of Trilobite Flexicalymene
Fragments of Other Cincinnati Trilobites
Drawings of Other Cincinnati Trilobites
Back to Trilobite Fragments Identifier
Dry Dredgers Home Page

The trilobite anatomy chart was done with a genuine Cryptolithus tessellatus courtesy of Evelyn Eastabrooks. The drawing in the anatomy chart is by Rich Fuchs.. The Cryptolithus fragments are from the collections of Bill Heimbrock.  The Cincinnati Trilobite Fragment Identifier was written and produced by Bill Heimbrock.

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