Trilobite Worm?

[sseth]

Here is one that has me perplexed.  I am always on the lookout for strange and new trilobites, especially from North Africa.  I picked this one up in Tucson.  At first I thought it may be just a fake, but it was from a trusted friend.  After inspecting it under magnification, it is the real deal.  It is nearly 4 inches long.  It is Devonian in age from Morocco, and I can not find mention of anything in the literature and wondered if anyone out there might have an idea.

[LordTrilobite]

I don't know the species. But yeah there are a number of Trilobites are have really weird smooth segments, giving them a very different look.

[Fossildude19]

Parahomalonotus planus, I think. 

[sseth]

5 minutes ago, Fossildude19 said:

Parahomalonotus planus, I think. 

I think you are correct.  Thank you.

[Fossildude19]

 

[Bandicoot]

I also picked up a few yesterday that I saw at the Co-Op on Oracle Rd. in Tucson . Nice to see what they are and I can add an ID tag to them now. Thanks.  

[Fossildude19]

Well,  don't make out that label just yet.

We may need Scott to help us out here.  @piranha

I am now seeing a similar one called Wenndorfia planus schrauti, and one called Parahomalonotus calvus ??  
Not sure which is correct, currently.  

[Fossildude19]

A little research brought up this thread from the Forum. 

I guess you would stick with Parahomalonotus on that.  

Maybe Scott can confirm?

[piranha]

The taxonomy can be confusing and difficult to follow, even for the professionals.  Sandford 2005 assigned the Moroccan species of Parahomalonotus to the new genus Wenndorfia.  Chatterton et al. did not recognize Wenndorfia when they published the new species: Parahomalonotus calvus from Morocco in 2006.  Another case in point: the link Tim provided to the AMNH Devonian Moroccan Trilobite Gallery has both genera listed when only one is valid.  Adding to the confusion AMNH cites Basse & Franke, 2006 for: Wenndorfia planus? schrauti.  In fact, that paper mentions: Parahomalonotus planus? schrauti.  Unfortunately overlaps and oversights in publishing are not uncommon.  Some of the subsequent literature still continues to publish the incorrect taxon.  Listed below is the most recent and reliable data from Basse 2012.

 

 

Sandford, A.C. (2005)
Homalonotid trilobites from the Silurian and Lower Devonian of south-eastern Australia  and New Zealand (Arthropoda: Trilobita: Homalonotidae).
Memoirs of the National Museum Victoria, 62(1):1-66

 

Basse, M., & Franke, C. (2006) 
Marine Faunen aus dem frühen Unteremsium (Unterdevon) des Givonne-Oesling-Antiklinoriums (Luxemburg).
Ferrantia, 46:7-41

 

Chatterton, B.D.E., Fortey, R.A., Brett, K.D., Gibb, S.L, & McKellar, R.C. (2006)
Trilobites from the upper Lower to Middle Devonian Timrhanrhart Formation, Jbel Gara et Zguilma, southern Morocco.
Palaeontographica Canadiana, 25:1-177

 

Quote

 

Basse, M. (2012)
Trilobites Africae: Catalogus typorum. 
Fossilium Catalogus I: Animalia, 150:1-311

 

Wenndorfia SANDFORD, 2005
Typusart: Homalonotus mutabilis KOCH, 1880.

Parahomalonotus calvus CHATTERTON et al., 2006: Holotypus : Vollständig eingerollter DCP UA 13381 (University of Alberta), ebd.: Taf. 33 Fig. 4–5 - Locus typicus : Nordöstlich vom Jbel Gara el Zguilma, Dra-Tal, Anti-Atlas - Stratum typicum: Linguipolygnathus serotinus-Zone der Conodontenchronologie, „Upper Member“ der Timrhanrhart-Formation (Niveau ZGEE1 oder ZGEE2 der Autoren; ebd.: 37 vs. 134), spätes Ober-Emsium.

 

Parahomalonotus planus? schrauti BASSE & FRANKE, 2006: Holotypus : PYG (Steinkern) SMF 53837 (Senckenberg Forschungsinstitut, Frankfurt am Main), SCHRAUT 2000a: Taf. 6 Fig. 3a–c; BASSE & MÜLLER 2004: Fig. 384 - Locus typicus : Profil Tadoucht II, Dra-Tal, Anti-Atlas - Stratum typicum: Merzâ Akhsaï-Formation („Rich 2“), Knollen graublauer Kalke, spätes Pragium (Details bei JANSEN 2001: 66) (ein früh unteremsisches Alter kann man nicht ausschließen).

 

 

 

[Fossildude19]

Thanks for looking into this for us, Scott.

Your expertise is appreciated.

Regards,