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Ceratarges aries trilobite prep story

Updated: Aug 25, 2019

To share some love for trilobites, a prep-story and a few prep-progress photos of a spiny trilobite, member of the order Lichida, from the Devonian deposits of Morocco, prepared by Alex Žagar. Not so long ago described new species, very rare Ceratarges aries sp. nov., from the El Otfal Formation. It is the rarest of the three newly-described Ceratarges, it only represented about 5% of the specimens found at the type locality. The dramatic cephalic, pygidial and thoracic spines have been prepared freestanding. It is an excellent example of the taxon with not often seen details preserved: natural free-standing spines, thorns on spines, eye-lenses, tuberculation and partially preserved vertical spines (characteristic for every 2. pleural segment on each side and a pair of spines on every 2. axial ring). Even the hypostome is preserved and could be seen in before-prep photo. All 100% natural, glued parts only.

In fossil preparation and in nature, perfection usually does not exist. We can only do our best to bring out that more or less good preserved specimen, but if you are on the look out for that perfect specimen - symmetrical, complete, well sized, well prepped, well composed on the matrix - sorry, there are always imperfections, however minimal. In fact, Ceratarges is one of those trilobites that you almost never see prepared good in detail and natural. With all the spines in a glass-like very hard matrix, it's a prep-challenge and not an easy bug to prep.

But some imperfections can make for a more interesting specimen sometimes... Or even tell a story! Most fossils end up being squashed flat by the pressure of the overlying deposits, but devonian deposits of Morocco are magnificent, everything was preserved three-dimensional, everything has been encased in sediment, which acted as a support, almost all at once. So when you remove layer by layer of matrix in the prep-lab, usually parts of many other trilobite specimens, Ostracoids, Brachiopods, Crinoids and other remains, hidden in matrix, come to light, revealing a more complete story of the last day of these ancient creatures. Some of this data is usually discarded, because there is no other way to get through, to the more significant remains. Unfortunatelly, part of the story is lost in the end.

However, this is what makes this Ceratarges even more interesting! Cyphaspis molt, debries, probably transported after the time of death, tumbling around by waves had deposited in layers of mud and gravel, just above the buried remains of Ceratarges. Debries crushed into Ceratarges, with a force so high that it broke a spine and deposited on the side. This is not an unusually story, actually, many spiny bugs suffer from similar damage or are molted remains; a perfect preserved fossil doesn't exist, there are only more or less good approximations and restorations. But here this story was at least partially preserved!

Ok, enough blablabla, let pictures talk...

Cross section of Ceratarges aries "before"

Close up, can you see 2 spines that don't belong there?

After many hours; more of the specimen and some Cyphaspis debries revealed

The beauty after many prep hours; photo after washing

Ceratarges aries sp. nov.; side shot (photo after washing); unfortunatelly thoracic spines are difficult to photograph.

Ceratarges aries sp. nov. after

And last one for size comparison. Thanks for reading and sharing!

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