Prep-story of devonian trilobite Koneprusia sp. from Issimoure

Updated: Jun 15, 2019

A short photo-prep-progress story of a fantastic #Koneprusia sp. from Issimoure Mt. (Quadrops couche), prepared by Alex Žagar. 100% natural!

Do you ever wonder why 90% of Koneprusia trilobites available in the market are destroyed (totaly burned skin, massacred) to almost unrecognizable condition, fake, painted over and more or less heavily restored?

If you try to prep one of these you start to undrestand. At over 70 hours of prep, this was a quick work for Koneprusia (although the % of details that could have been preserved in this type of matrix even if 40 hours more were spent is relatively low and would make no sense). In commercial preparation, there's always a choice between the prep quality and the time-costs, but the usual Moroccan way of quick-prep can take much less time to prep as a careful work. All quick preparations result in more or less damage, so price alone does not make a bargain a good deal. Price does not guarantee authenticity either, but you can easily judge the work when prep-progress photos are shared and TDI is one of the few very professional sellers of only the best quality and authentic trilobites, that deserves your trust 100% even without prep photos!

What I'm talking about? You can see the difference between a careful and a quick prep in photos and if you google or search "Koneprusia brutoni" or "Koneprusia" in ebay...

Koneprusia sp. from Issimoure Mt., profesionaly prepared by A.Ž. - high quality as usually available in TDI

Quick preped Koneprusia dahmani; a different type, different locality, but typical commercial quality - considering prep difficulty not so bad prep-work actually, it can get a lot worse (many - from hard limestone of Oufaten and Issimoure Mt. - are even more massacred; only spines glued, some spines and parts restored, paint, some details burned and airscribe damage).

I'm not gonna go into details about the difference between quickly-massacred-preped commercialy trilobites and careful-meticoulous-preparations, and why good quality comes with a price (ok, Koneperusia is probably not the best example, because it's one of the more difficult trilobites to prep). Just trying to explain why a good Koneprusia is difficult to find or costs a lot of $ (and still not enough, compared to price of trilobites in USA or Russia and difficulty to prep).

There are 2 ways to #prep spiny #trilobites: You can remove spines (and glue back later) or hope you don't break any spines. When you remove the long curved spines on a Koneprusia, it’s a real nightmare to glue spines back... If you don’t remove the fragile spines, things get more difficult because of the limited space to work, "dead-angles", curves, very hard matrix etc. In a very hard matrix from Oufaten or Issimoure things get even more tricky!

There are several types of Koneprusia, with the main difference in position and number of the spines on axis, some with more pronunced tuberculation, some with more curved spines, but what all have in common is that every prep-step is more difficult; most trilobite get easier when more of the specimen is revealed and preped out. However, Koneprusia is an exception among spiny trilobites, long curved spines and secondary spines make preparation a nightmare, step by step the nightmare gets worse. One mistake and you're f...

So, in short, that's the answer to the first question - the difference between a careful, meticulous preparation and a quick, commercial preparation of a #fossil can be extreme. A lot of effort, time and difficult work in finding a complete (non-molted) specimen and in a good prep...

The Koneprusia sp. trilobite presented below is in top 1% of what we can see in the market, besides it's also very large and a rare type, without the spines on first 2 axial rings (only tubercules), typical for Quadorps couche locality in Issimoure... No point writting more, photos say all:

No pic of the cross section before prep-work, this is after over a dozzen hours of needle-work and sandblasting in a very hard matrix; all rock covering the cephalon and thorax (front) was removed.

Many hours later...

Other side; preservation of details is remarkable...

Fast forward...but many many hours... No spines were removed and without removing any spines it's tricky to get to this point. And from here things get even more tricky...

Tight space to work down to the pleura and around the fragile spines; any micro-crack caused by vibration will result in damage in next steps...1 glued part (cross section)

Many hours later... Luckily no breaks, all spines still standing (1 spine was missing, there's probably a story to it, was not found in matrix around the trilobite and looks like a healed injury).

Really a fantastic preserved bug and a great prep! Figured it deserves a stroy! 100% natural! 1 glued part only, no resto, no repair, no paint! Hope you like, thanks for reading and sharing!;)

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