Real Morocco Trilobites or not?

[Golem]

HI guys,

 

I know Morocco fossils are a general no no for entry level folks like me. However this particular piece caught my eye and I quite like how it looks.
It has 2 Phacops and 1 Paralejurus on the same matrix
Would be great if I can get some more insight from the experts on this forum.
Thank you.

[snolly50]

I believe I recall this piece being discussed in a previous post, but can't find it. Does anyone remember?

[ynot]

They look good to Me.

But let's see what @piranha and @LordTrilobite have to say.

[LordTrilobite]

Yup those trilobites are real. The only concern would be if these are composited onto one piece of matrix or that they actually belong together. I don't see any parts that look suspicious and there's also a glued break that points to it being real.

 

So I'd say it's good.

[piranha]

The phacopids are not 'Phacops', instead they are Reedops cephalotes hamlagdadianus.  The other trilobite is Paralejurus hamlagdadicus.

 

 

[aeon.rocks]

First: Real ...could have some restored parts, but in case of trilobites (ALL in general) that`s more or less normal imho; pieces of matrix are usually glued together, cracks filled, minor pieces eroded or lost etc. But depends what you like...

 

Second: Why do you think that Moroccan trilobites in general are no no for "entry level collectors"? All kinds of fossils can be faked nowadays! It`s always good to be careful, but in fact, the market is so flooded with REAL common moroccan trilobite species priced so low, that most collectors don`t even realize how much time and effort is invested in some of these magnificent creatures... In my opinion, if you like devonian or ordovician 3D prepped bugs you will have a hard time buying nicer trilobites for the money. Moroccan prep quality is usually commercial grade, but I don`t blame them, not many collectors are willing to pay high sums for detailed prep... So, if you are "entry level collector" and you would like to add trilobites to your collection, but don`t care if it`s commercial grade and don˙t want to spend a fortune on Russian or USA ordovician/devonian species I would say Moroccan trilobites are a good way to start, with caution though - don`t expect to find rare spiny species for 40$ in example...

[Douvilleiceras]

All the trilobites are real, but are roughly prepared. On the Paralejurus, I can see terrace and eye detail that would be nearly impossible to fake. In addition to this, Paralejurus is common and the prepping is consistent with Morocco (note the nicks on the exoskeleton). With the Phacopids (your trilobites are from the family Phacopidae, but are not representations of its type genus, Phacops), there are discovery cracks, evidence of repair with glue, some slight flaking on the exoskeleton, and eye detail ( even though one's eye facets were airscribed away), all pointing to it being real. 

[Golem]

Thank you all for the detailed response. I appreciate the knowledge and suggestion that you guys provided on this piece.

I do have another question that is not related to the trilobites shown in the picture.
When I look at the different fossil samples of Cheirurus (Crotalocephalus) gibbus, I am having hard time to see the details of the compound eyes.
Does it have anything to do with its anatomy or simply due to fossil preparations (Or I just don't know where to look). 
I am lacking the knowledge of anatomy for this type of trilobite and unable to find relevant information online. Any information will be much appreciated.

If it is too far off topic please point me to the right section of the forum.

 

[Douvilleiceras]

6 hours ago, Golem said:

Thank you all for the detailed response. I appreciate the knowledge and suggestion that you guys provided on this piece.

I do have another question that is not related to the trilobites shown in the picture.
When I look at the different fossil samples of Cheirurus (Crotalocephalus) gibbus, I am having hard time to see the details of the compound eyes.
Does it have anything to do with its anatomy or simply due to fossil preparations (Or I just don't know where to look). 
I am lacking the knowledge of anatomy for this type of trilobite and unable to find relevant information online. Any information will be much appreciated.

Crotalocephalina has holochroal eyes with thousands of tiny facets, so they wouldn't be visible without magnification. Only the Suborder Phacopina has schizochroal eyes - the type you are looking for. There is a third type of eye, called the abathochroal eye, which has the least number of lenses, but it is only found in minute trilobites of the Suborder Eodiscina, Order Agnostida. 

 

Here is a great resource for an introduction: https://www.trilobites.info/eyes.htm

[piranha]

3 hours ago, Douvilleiceras said:

...There is a third type of eye, called the abathochroal eye, which has the least number of lenses, but it is only found in minute trilobites of the Suborder Eodiscina, Order Agnostida. 

 

 

Although it has been generally accepted since Jell 1975, that there are three types of trilobite eyes, more recently it has been suggested that there are only two types of eyes; holochroal and schizochroal. The abathochroal eye described only from eodiscid trilobites, is most likely a paedomorphic holochroal eye.

 

 

text from:

 

Zhang, X-G., & Clarkson, E.N.K. (2012)
Phosphatized eodiscoid trilobites from the Cambrian of China.
Palaeontographica Abteilung A., 297(1-4):1-121   PDF LINK

 
The eyes of eodiscoids were described as abathochroal by JELL (1975b), who considered them to be distinct from holochroal eyes since the lenses were somewhat separated from one another, along with a summary that the eyes of eodiscoids resemble holochroal eyes in five respects, and there are eight differences from the schizochroal type. Of these, two key features for establishing these eyes as a separate type are the lenses not being in contact with any of the surrounding lenses, and each lens possessing its own corneal membrane. However, with more and more phospatized material being documented, and especially with the more fully detailed morphological examination of the visual surface of the eodiscid Pagetides, our new observations do not support the view that abathochroal eyes are distinct from the other two well-known types.
 
For instance, JELL (1975b) believed that each of the individual lenses carried its own corneal cap, but the fact that the outermost thin layer of the visual surface can flake off, taking with it many lenses together, rather than just a single one, casts doubt on this interpretation. Actually, the internal surfaces of some librigenae with the visual surface attached show that some of the fine lenses are polygonal in outline (Plate 16, Fig. 7), rather than circular as seen from the external surface. This is because these lenses remained in close contact as they grew towards a centre point of the visual system, and this has led to the deformation of the outline of lenses from circular to mostly hexagonal, as well as a few pentagonal and quadrilateral (also see ZHANG & CLARKSON 1990, pl. 2, figs 2-6). Moreover, it is now known that the juveniles of holochroal-eyed trilobites have separated lenses (CLARKSON & ZHANG 1991, CLARKSON & TAYLOR 1995), and that they are likewise separated in the paedomorphic Ctenopyge ceciliae (CLARKSON & AHLBERG 2002).
 
If eodiscoids are indeed paedomorphic derivatives of holochroal-eyed polymerid trilobites, is it not likely that they would have separated lenses too? It may be, therefore that the concept of abathochroal eyes as a separate eye type, though adopted earlier (CLARKSON 1997) is no longer sustainable, for the moment we leave the question open. In the descriptive part of the text, accordingly, we describe the eyes of eodiscids as abathochroal, because this term to date remains absolute as only known from eodiscoid trilobites.

[Malcolmt]

All real, Very rough prep and looks like a composite to me. Very unlike to have three the fossils ending up in three different planes and orientation.When one is lying flat you are very unlikely to have another perpendicular to it.

[Golem]

Thanks for the informative readings. Feels like I am going back to university again.

Attached pictures is another fossil that I am interested at.
The specimen looks good to me except I have some concerns with the lower thorax and pygidium part of the fossil (as indicated by the red circle and the arrow pointed area).
I have also attached the same picture without my "markers" for clarity.
As always any information from you guys are highly appreciated and valued.

 

 

 

 

 

 

 

Edited September 17, 2017 by Golem

[Douvilleiceras]

It is a real Dalmanitid trilobite, and is of the genus Zlichovaspis. Hailing from the Moroccan Devonian, this trilobite has decent preparation, and even has a lower half of a Crotalocephalina present on the matrix. However, the area you highlighted does appear to be reconstructed. The uneven line where the trilobite meets the matrix suggests paint, which, when combined with the different appearance, makes me think that there are some reconstructed areas in that region.

Edited September 18, 2017 by Douvilleiceras
Terminology Error (Thanks for pointing this out, piranha!)

[piranha]

Although Zlichovaspis is in the Order Phacopida, it should be referred to as a dalmanitid, a member of the Dalmanitidae family.

 

 

 

 

[aeon.rocks]

10 hours ago, Malcolmt said:

Very unlike to have three the fossils ending up in three different planes and orientation.When one is lying flat you are very unlikely to have another perpendicular to it.

 

It`s a bit unusual in general, but common and not unlikely in the case of moroccan devonian material I`ve seen.

 

Quote

However, the area you highlighted does appear to be reconstructed. The uneven line where the trilobite meets the matrix suggests paint, which, when combined with the different appearance, makes me think that there are some reconstructed areas in that region.

 

Zlichovaspis looks real to me. Sure, some minor restorations are possible, but if different color on the pygidium bothers you, that`s more likely the result of diagenesis. Due to the microstructures on the skin Zlichovaspis is usually not the easiest specie to prep, that often results in damage or burnt skin. In the case of Zlichovaspis in general matrix is very sticky and as we can see in the photos, parts of the specimen were covered by a limonite layer, giving them a characteristic bright orange or brown color. It`s not possible to conclude if the specimen is 100% real from these photos, some minor pleural segments could be "restored", but the different appearances could aswell be related to prep issues mentioned.

 

Also, from a quick look at the photos I don`t see any uneven lines where the trilobite meets the matrix... I guess you might be refering to the different color of "smoothed out" matrix (bright whiteish/yellowish) and darker "non-smoothed out" matrix (brownish) around the pygidium. That`s not a sign of paint, it`s just how the matrix around the trilobite was cleaned in a hurry.

 

 

[Golem]

I have decided to purchase the Zlichovaspis. It is slightly more expensive than the trio but I think it is a better buy based on the assessments you guys provided here.
Thanks!