Trilobite - Drotops megalomanicus (Devonian, Ma'der Basin, Morocco)
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Estimated value
$150 - $450Rarity
Average(4/10)Category
FossilsEra
Middle Devonian (approx. 390 Ma)Origin
MoroccoVisual assessment
TRILOBITE - DROTOPS MEGALOMANICUS (DEVONIAN, MA'DER BASIN, MOROCCO): IDENTIFICATION
This specimen is a large phacopid trilobite, specifically Drotops megalomanicus, characterized by its robust, convex cephalon and distinctive schizochroal eyes with large, visible lenses. The exoskeleton exhibits significant tuberculation, a diagnostic feature of this genus from the Middle Devonian strata of Morocco. The thorax consists of eleven well-defined segments leading to a rounded pygidium. This example is prepared in a 'prone' position, though it shows significant evidence of aggressive mechanical preparation and potential resin-based reconstruction on the pleural tips and cephalic border.
Compare with other fossils in the archive: Fossil Fish Positive/Negative - Vinctifer comptoni (Cretaceous, Santana Formation, Brazil), Proboscidean Innominate (Fossilized Elephant or Mammoth Pelvis), Trilobite - Drotops megalomanicus (Devonian, Ma'der Basin, Morocco) 11cm, Prepared.
SCARCITY
Typical antique shop fare. Requires some searching but regularly available. This is where most genuine antiques fall.
Typical Characteristics
- Standard antique shop items
- Regularly available
- Moderate collector interest
Observed factors
- High prevalence of 'carved' or composite specimens of this specific genus from Morocco
- Uniform dark staining often indicates covered repairs or resin fills
- Lack of clear differentiation between the fossil and the surrounding matrix in several areas
PALEONTOLOGIST'S TAKE
Paleontology Specialist
The taxon is unmistakable, but the high degree of commercial preparation and potential enhancement common in these Moroccan imports requires a cautious identification regarding 'all-natural' status.
KEY EVIDENCE
- 1Morphology consistent with Drotops megalomanicus, specifically the oversized tuberculated glabella.
- 2Schizochroal eye structure visible in the cephalon profile.
- 3Matrix style and coloration typical of the Ma'der Basin limestone.
- 4Preparation style (air-scribe marks) typical of commercial Moroccan workshops.
UNCERTAINTIES
- •The 'wet' or greasy appearance suggests a surface sealant (varnish or oil) used to darken the fossil.
- •Possible reconstruction on the left side of the cephalic border where the texture becomes smoother.
- •The lack of visible sutures might suggest some 'enhancement' of the segments with carving tools.
WHAT WOULD IMPROVE CERTAINTY
- →Perform a UV light test to identify resin reconstructions (resin will fluoresce differently than natural calcite).
- →Use a needle to test the hardness of the matrix vs. the fossil; resin fills will feel softer and 'plastic'.
- →Check for symmetrical discrepancies that might indicate a 'composite' made of two different trilobites.
COLLECTOR GLOSSARY (3 terms)
- Tuberculation
- The presence of small, rounded bumps or nodules on the exoskeleton of the trilobite.
- Schizochroal eye
- A type of compound eye found in phacopid trilobites where each lens is separated by sclerotic tissue.
- Prone
- A preservation position where the trilobite is lying flat, as opposed to 'enrolled' (curled into a ball).
CONDITION & GRADE
Grading breakdown
The specimen lacks the high-fidelity detail of 'Collector Grade' examples; the eye lenses are obscured by prep-scuffs and the tubercles appear worn or partially sanded.
Condition
Significant mechanical damage is visible on the right pleural lobes. The uniform black color suggests the application of a 'shoe polish' or potassium permanganate stain common in Moroccan preparation labs to hide repairs or composite sections.
Weight & feel
Substantial and dense, likely weighing between 0.8 kg and 1.5 kg depending on the amount of remaining limestone matrix.
SPECIMEN MARKET VALUE
Updated: May 11, 2026
Similar commercial-grade Drotops specimens frequently sell on eBay and at the Tucson Gem and Mineral Show for between $200 and $400 USD.
Who buys this
Novice collectors, educators, and interior designers looking for a large, impressive 'conversation piece'.
What increases value
- •Size (Drotops is valued for its bulk)
- •Eye lens preservation (if the lenses can be individual counted, value increases)
- •Natural 'matrix' presentation
What lowers value
- •Heavy reconstruction or resin parts (can lower value by over 50%)
- •Aggressive preparation marks that obscure biological detail
What makes top-tier examples
- •Free-standing spines (if applicable to the subspecies)
- •No chemical staining or paint
- •100% original calcite with no composite parts
Grade & condition
Completeness of the thorax, clarity of the eye lenses, and the ratio of natural rock vs. restored fossil material.
Rarity & demand
For informational purposes only, not a formal appraisal.
Another look, another find
Fossil Fish Positive/Negative - Vinctifer comptoni (Cretaceous, Santana Formation, Brazil)
Proboscidean Innominate (Fossilized Elephant or Mammoth Pelvis)
Trilobite - Drotops megalomanicus (Devonian, Ma'der Basin, Morocco) 11cm, Prepared
Megalodon Tooth - Otodus megalodon (Miocene to Pliocene)
Petrified Wood (Silicified)
Megalodon Tooth - Otodus megalodon (Miocene to Pliocene)
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