Solnhofen Gyrodus sp.
Place of discovery: Langenaltheim, Langenaltheimer Haardt; Solnhofener Revier/ Germany
Lithostratigraphy: Lower Tithonian, White Jurassic Group, Altmühltal Formation, Upper Solnhofen Subformation
Biostratigraphy: Hybonotum zone, rueppelianus subzone, rueppelianus horizon
Age: approx. 150.8 – 152 million years +/- 2 million years
Size plate and counter plate: 120 x 100 cm
Size of fossil: approx. 90 cm (largest size)
Showpiece: Giant “moonfish” – a fossil icon from the Upper Jurassic of Solnhofen.
Authentic – in original matrix, not reburied. With proof of provenance.
Offered on behalf of the customer. RESERVED
Gyrodus – The specialized hard parts specialist of the Solnhofen archipelago
The genus Gyrodus belongs to the order Pycnodontiformes (flatfish) and is a striking representative of the specialized fish fauna of the Solnhofen limestone slabs. With its high-backed, nearly circular body shape, it differs markedly from the spindle-shaped predatory fish of open water. Gyrodus occupied the ecological niche of a “durophagous” consumer specialized in cracking hard-shelled food.
Scientific Classification and Morphology
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- Adaptation to the reef habitat: Its strongly laterally flattened, disc-shaped body allowed for great maneuverability within the complex structures of the sponge and coral reefs that bordered the lagoons.
- Pavement-tooth dentition: The most striking feature of Gyrodus is its specialized dentition. It consists of several rows of rounded, flat cobblestone teeth on the vomer (plowshare bone) and the prearticulars (lower jaw bones), which functioned like a grinding mill for cracking open mussels, corals, or crabs.
- Fin margin: The dorsal and anal fins are elongated and form an almost symmetrical margin along the rear third of the body, which is typical of this evolutionary lineage.
The fine details – what collectors look out for:
- Pavement-like tooth rows: In high-quality specimens, the glossy tooth rows in the skull region are often visible as a continuous structure. The preservation of these hard tooth structures is considered an important diagnostic feature.
- Partial armor: In contrast to the fully armored Dapedium species, often only the front part of the torso is covered with massive scute-like plates, while the rear part was unscaled. As a result, the bone structure is preserved in the front section, whereas the rear section tends to retain the imprint of the soft tissues.
- Tail fin: The robust, sickle-shaped tail fin is often very prominently developed and, in well-preserved specimens, forms an aesthetically pleasing conclusion to the body contour.
A highlight for every Solnhofen collection
Gyrodus is one of the iconic fossils of the Jurassic Sea and is highly sought after by collectors due to its aesthetics. A fossil like this is not just an investment, but a window into a time when Bavaria was still a subtropical island paradise.
