Ceratonurus - a rearticulation
Cross-section 1: Ceratonurus from ventral side
- left: Pygidium hidden under the rock, right: thick spines of the Cephalon
Cross-section 1: Ceratonurus from ventral side
- left: Pygidium hidden under the rock,
right: thick spines of the Cephalon
Cross-section 2: right side of the pleuraes, cranidium on the left
Cross-section 2: right side of the pleuraes,
cranidium on the left
Getting started: the cranidium is deep inside the
rock and the left librigena is disarticulated
Getting started: the cranidium
is deep inside the rock
and the left librigena is
disarticulated
The right librigena lies close to the pygidium
The right librigena lies close to
the pygidium
The spine of the right librigena lies behind some pleural spines
The spine of the right librigena
lies behind some pleural spines
The left librigena will be carefully removed
The left librigena will be
carefully removed
The thorax shows very attractive long pleural spines
The thorax shows very attractive
long pleural spines
A removed spine showing excellent tubercles
A removed spine showing
excellent tubercles
The thorax was glued together and the cranidium removed
The thorax was glued together
and the cranidium removed
After the matrix had been formed, it was time to put all removed parts back in place
After the matrix had been formed,
it was time to put all removed parts back in place
The final result after about 60 hours of detailed and careful work
The final result after about 60 hours
of detailed and careful work
The locality of Jorf offers up a lot of well preserved Devonian trilobites. Amongst which are extremely rare species, such as this Ceratonurus, which I received as a commissioned work piece. Complete specimens are virtually impossible to obtain and so I was delighted to be able to prepare this rarity.
The so called “glass limestone” from Jorf is a very though, nearly flint-like type of stone, which is almost exclusively workable with a sand blaster. Usually the matrix separation from the fossil is quite poor. Although, when carefully preparing the fossil, the shell details can still be secured.
This specimen was an exuviae and was, as requested by the owner, rearticulated, which means that the dislocated shell pieces were removed from the matrix and replaced at their original spots. Considering the extreme rarity and according high worth of this trilobite this presents an entirely reasonable decision. The entire work progress was extensively documented.
Fossil: Ceratonurus sp.
Locality: Jorf (Morocco)
Formation: Devonian
Length of the trilobite: 3 cm
Work required: 60 hours