Leviceraurus or just plain Ceraurus?

[Kane]

Just seeking to verify whether or not this is a Leviceraurus mammiloides or just plain Ceraurus sp. Found yesterday in the Lindsay Fm (Ordovician) in Ontario. If the former, it is sadly missing the long pygidial spines.  Prepping this one is a bit of a challenge as it is fragile in places, and the matrix is very stubborn (I may have to get someone else to fix this one). I've done what I could with abrasion.

 

Specimen is very small: 1.5 cm.

 

For comparison, the specimen and the line illustration from Hessin's book. The genal spines don't look quite long enough to be a Levi, but the spine appears broken off before the termination point.

[Raggedy Man]

 

 

Heres a Leviceraurus mammilloides. The spines aren't as exaggerated as they are in the drawing. Too bad the pygidium or the cephalon aren't complete. Would make identification easier....lol. Hopefully @piranhacan give more insight on this one. Either way, great find. I'd love to have sites with more of a chance to find these guys more complete than findng a cephalon or a pygidium. Though im not complaining, I did find my no.1 bucket list trilobite last year. 

[Kane]

12 minutes ago, Raggedy Man said:

Im going with Ceraurus sp. 

 

Heres a Leviceraurus sp. The spines aren't as exaggerated as they are in the drawing. Too bad the pygidium or the cephalon aren't complete. Would make identification easier....lol. Hopefully @piranhacpircan give more insight on this one. Either way, great find. I'd love to have sites with more of a chance to find these guys more complete than findng a cephalon or a pygidium. Though im not complaining, I did find my no.1 bucket list trilobite last year. 

There may be more cephalon underneath the matrix... but I'm at a limit of what the tools will do (without risking damaging it). What set me off was the arrangement of the tubercles on the glabella. I do wish the pygidial spines preserved.  Haven't found one yet with the tail nice and preserved.

[Raggedy Man]

14 minutes ago, Kane said:

There may be more cephalon underneath the matrix... but I'm at a limit of what the tools will do (without risking damaging it). What set me off was the arrangement of the tubercles on the glabella. I do wish the pygidial spines preserved.  Haven't found one yet with the tail nice and preserved.

Yeah that soft shale can really hinder prep sometimes. Best of luck! I hope you're able to get it prepped a little more to see if the cephalon is complete. It would be sweet if it turned out to be a Leviceraurus.I added another image to show the full specimen. 

[Tidgy's Dad]

It hope it is Leviceraurus. 

Not sure.

Lovely find, anyway! 

[Kane]

Just an update: my preparator friend completed this bug and confirmed it is indeed Leviceraurus mammilloides, just missing the long pygidial spines. Despite that, it is still a lovely and somewhat rare bug in this formation. 

[ynot]

[Fossildude19]

Cleaned up real nice, Kane! 

Congratulations!

[Walt]

9 minutes ago, Kane said:

Just an update: my preparator friend completed this bug and confirmed it is indeed Leviceraurus mammilloides, just missing the long pygidial spines. Despite that, it is still a lovely and somewhat rare bug in this formation. 

silly newbie question here.  Perhaps you can point me to the answer if this is not the appropriate thread.

I notice your preparator friend did not go under the specimen but cleaned up the surface (looks great, btw).  Is the "rule" to lift as much of the specimen out of the matrix as the fragility of the specimen will allow?  Sorry if this is not clear..... I see some specimens (not just bugs) where the matrix is removed well under the sides and others where just the surface is cleaned up.  How do you know where to stop?

[Kane]

1 minute ago, Walt said:

silly newbie question here.  Perhaps you can point me to the answer if this is not the appropriate thread.

I notice your preparator friend did not go under the specimen but cleaned up the surface (looks great, btw).  Is the "rule" to lift as much of the specimen out of the matrix as the fragility of the specimen will allow?  Sorry if this is not clear..... I see some specimens (not just bugs) where the matrix is removed well under the sides and others where just the surface is cleaned up.  How do you know where to stop?

I think it very much depends on orientation and thickness of the shell. If the shell is thicker (such as on Russian asaphids or on nicely inflated Eldredgeops coming out of Penn Dixie), you can trench down a bit deeper to expose them. Knowing where to stop can be tricky, which is why it is helpful to know the morphology of the bug to determine where certain features terminate. That being said, proceeding very slowly and cautiously is always a good idea, and to do so under a microscope. Thinner stuff will be a surface job, such as for most Cambrian trilobites, and generally those appearing in thinly-bedded shales where the trilobite is crushed flat.

[Walt]

excellent.  Thank you.

[dalmayshun]

I think your friend did a great job prepping, considering how fragile you said the piece was, and congrats on finding such a cool bug.

[ricardo]

Great trilobite! Congratulations!  

[GerryK]

On 5/28/2018 at 12:59 PM, Raggedy Man said:

 

 

Heres a Leviceraurus mammilloides. The spines aren't as exaggerated as they are in the drawing. Too bad the pygidium or the cephalon aren't complete. Would make identification easier....lol. Hopefully @piranhacan give more insight on this one. Either way, great find. I'd love to have sites with more of a chance to find these guys more complete than findng a cephalon or a pygidium. Though im not complaining, I did find my no.1 bucket list trilobite last year. 

The picture of the above Leviceraurus is not a Leviceraurus mammilloids but of an undescribed species of Leviceraurus. There are two different species of Leviceraurus in the Lindsay Formation. The difference between the 2 species is the way the pygidial spines come of the pygidium, outward like the line drawing of L. mammilloides or inward like the picture above.