Cryptolithus bellus collar

[Fossil Claw]

I found this Cryptolithus bellus collar that looks to be fairly complete in Northern Kentucky today. I am never found anything but fragments of collars before.

 

Trying to figure out if this is the top or the bottom in the trilobite and whether or not it's worth prepping to see if the rest of it is there or not.

 

I'll post more pictures after I get it home and clean it.

 

Thoughts?

[Pumpkinhead]

My initial thoughts would be that you are looking at the underside of the trilobite as the glabella of Cryptolithus is quite convex and would likely be visible from a dorsal view (If present). I'm also fairly certain that the collar should slope downwards away from the cranidium, so if what you are looking at is in fact the ventral view of the collar you would expect it to have an angle and slope downwards to the inside rather than the outside.

 

If you can't understand my convoluted attempt at explaining what I see then the bottom right image of Cryptolithus tesselatus should be illustrative. Notice the way the collar "slopes" away from the cheeks and glabella.

[piranha]

Shaw & Lespérance 1994 classify eastern North American Cryptolithus as morphs rather than distinct species, synonymous with the type species: Cryptolithus tessellatus

 

 

"lt is our contention that all specimens described from eastern North America by many writers under the names Cryptolithus tessellatus Green, Cryptolithus lorettensis Foerste, and Cryptolithus bellulus (Ulrich) or synonyms thereof defined by Whittington (1968) or Hughes et al. (1975) are morphs, races, or regional variants of Cryptolithus tessellatus.  These specimens thus do not merit formal taxonomic status as species, sibling species, or subspecies."

 

Shaw, F.C., & Lespérance, P.J. 1994
North American biogeography and taxonomy of Cryptolithus (Trilobita, Ordovician).

Journal of Paleontology, 68(4:)808-823

 

 

"Bassler (1915) dispatched Ulrich’s (1878) Trinucleus bellulus to Cryptolithus.  Curiously, Ulrich did not compare C. bellulus to the well-established C. tessellatus Green, 1832; more recent workers (for example, Whittington, 1968; Hughes et al., 1975; and Shaw and Lespérance, 1994) consolidated C. bellulus within that species.  Babcock (1996) recognized C. tessellatus as the only species of Cryptolithus from the Ohio Ordovician."

 

Brandt, D. S., & Davis, R.A. 2007

Trilobites, Cincinnati, and the “Cincinnati School of Paleontology”.

In: Mikulic, D.G., Landing, E., & Kluessendorf, J, (eds.)

Fabulous Fossils: 300 Years of Worldwide Research on Trilobites.

New York State Museum Bulletin: 507:1-248   PDF LINK

 

 

"Cryptolithus which is sometimes called the lace-collar trilobite (Davis, 1985) because of its distinctive cephalic fringe, is present through much of the Cincinnatian Series strata of southwestern Ohio.  Most specimens have been collected from the Kope, Fairview, and Grant Lake Formations.  Only one species, C. tessellatus Green, seems to be present in the Cincinnatian of Ohio (Shaw and Lespérance, 1994).  In some older literature, this species was identified as C. bellulus (Whittington, 1968)."

 

Babcock, L.E. 1996

Phylum Arthropoda, Class Trilobita.

In: Feldmann, R.M., & Hackathorn, M. (eds.) Fossils of Ohio

Ohio Division of Geological Survey, Bulletin 70:90-113

 

 

Several species of Cryptolithus were historically identified in Upper Ordovician strata of eastern North America (see, for example, Whittington, 1968).  At least two species, C. tessellatus and C. bellulus, were recognized in Kentucky and surrounding states.  Differences in the various species were based on the number of arcs of perforations or holes in the frill or slight shape differences.  Subsequent statistical analysis of specimens found that slight variations in shape and the number of arcs or pits varied in all species and that the specimens were better considered variations (morphs) of one species rather than multiple species.  Presently, all of the Upper Ordovician Cryptolithus from the eastern United States are considered Cryptolithus tessellatus (Shaw and Lespérance, 1994).

 

text from:  Kentucky Geological Survey

[DevonianDigger]

I too, believe that you are looking at the ventral side of the anterior margin. The glabella, and perhaps even a complete cephalon may be contained within. Very cool!

[Fossil Claw]

Turns out I also found a Meadowtownella crosotus.

 

At the very least it's a partial but it looks like the whole thing could be there we'll have to prep it to find out.

[ynot]

17 minutes ago, Fossil Claw said:

the whole thing could be there we'll have to prep it to find out.

[Castle Rock]

In your third photo, I believe that I can see what MIGHT be a complete Cryptolithus ceph, just below the inch cube?   Please post after prep pictures....CURIOUS!    Dave 

[RJB]

Good luck.  I hope one or both are complete for you.

 

RB

[Fossil Claw]

12 minutes ago, RJB said:

Good luck.  I hope one or both are complete for you.

 

RB

Thanks.

 

Given the rarety I am going to likely turn it over to a pro to do for me.