Description
Historic 1929 Collection Ammonite from Bavaria
This carefully chosen fossil is a genuine Ataxioceras (Parataxioceras) desmoides desmoides ammonite from Kirchberg bei Pappenheim, Bavaria, Germany. It originates from the traditional Malm Gamma 1 succession and dates from the Lower Kimmeridgian Stage of the Upper Jurassic Period, within the ammonite-defined Platynota Zone.
The specimen comes from a 1929 collection, giving it an additional historical dimension alongside its geological importance. Fossils preserved within older collections are especially appealing because they connect modern collectors with the long tradition of European palaeontology and the detailed study of Germany’s Jurassic rocks.
Its precise taxonomic identification, recorded locality, traditional bed designation and historic collection provenance make this an excellent specimen for collectors of German ammonites, Upper Jurassic fossils and scientifically documented natural-history pieces.
Ataxioceras Parataxioceras Classification
The complete identification Ataxioceras (Parataxioceras) desmoides desmoides records the genus Ataxioceras, the subgenus Parataxioceras and the nominate subspecies desmoides desmoides. Repetition of the species name identifies it as the subspecies carrying the same name as the species itself.
Ataxioceras belongs to the extinct cephalopod order Ammonitida and is associated with the family Ataxioceratidae, a group of strongly ornamented ammonites characteristic of parts of the Kimmeridgian. Parataxioceras is recognised as a subgenus containing comparatively evolute ammonites with pronounced ribbing and complex changes in ornamentation during growth.
The species was established by the German palaeontologist Ludwig Wegele, whose important work on Franconian Jurassic ammonites was published in 1929. This date is particularly appropriate for a specimen retaining provenance from a 1929 collection.
Distinctive Ribbed Ammonite Morphology
Ataxioceratid ammonites are valued for their elaborate shell sculpture. The shell of Ataxioceras is generally compressed and moderately involute to evolute, with a visible central umbilicus and numerous ribs extending across the flanks.
Primary ribs begin near the umbilical margin and may divide more than once as they pass towards the outer edge of the shell. This repeated branching can create dense bundles of secondary ribs, producing the intricate ornamentation typical of the group. Irregular constrictions may interrupt the rib pattern at intervals, while later growth stages can display changes in rib strength, spacing and direction.
The exact characteristics visible on this individual specimen depend upon its growth stage and natural preservation. It may show clearly defined whorls, bifurcating or polyfurcating ribs, sections of the central umbilicus, preserved shell material or a natural internal mould formed by sediment that hardened inside the original shell.
Natural wear, incomplete whorls, areas of attached matrix, mineral deposits and variations in rib definition are authentic features of a fossil preserved for more than 150 million years.
Chambered Shell and Ammonite Biology
The original shell was divided internally into numerous chambers separated by curved walls called septa. The living ammonite occupied the final and largest section, known as the body chamber, while the older chambered part formed the phragmocone.
A narrow tube called the siphuncle connected the chambers near the outer margin of the shell. By adjusting the proportions of liquid and gas inside them, the animal could regulate its buoyancy and maintain its position in the Jurassic sea.
As the ammonite grew, it added new shell material around the aperture. It periodically moved forward into a larger living space and constructed a new septum behind itself. This continuous growth produced the spiral shell and recorded changes in ribbing and whorl proportions throughout the animal’s life.
Ammonites were marine molluscs belonging to the cephalopod lineage and were related to modern squid, cuttlefish, octopuses and nautiluses. They became highly diverse during the Jurassic and are now among the most important fossils used for dating marine sedimentary rocks.
Platynota Zone Biostratigraphy
This fossil comes from the Platynota Zone, an ammonite-defined interval within the Lower Kimmeridgian of the Upper Jurassic. The zone takes its name from Sutneria platynota, a characteristic ammonite used to recognise this part of the geological succession.
The Platynota Zone contains several distinct ammonite assemblages and biohorizons. Research on southern German faunas recognises a desmoides biohorizon within the zone, named for ammonites belonging to the desmoides group. This gives the fossil particularly strong biostratigraphical relevance: its taxonomic identity is directly associated with a finely resolved interval of Lower Kimmeridgian time.
Ammonites are effective index fossils because they evolved rapidly, were abundant and occupied broad marine regions. Their changing assemblages allow geologists to correlate individual beds between separate exposures and reconstruct the detailed sequence of Upper Jurassic marine events.
Malm Gamma 1 Geology
Malm Gamma 1 is a traditional southern German lithostratigraphical designation applied to Lower Kimmeridgian strata associated with the Platynota Zone. The term “Malm” was historically used for Upper Jurassic rocks, while the Greek-letter subdivisions distinguished successive parts of the regional limestone and marl sequence.
Malm Gamma 1 is widely associated with the lower Platynota Zone in the Franconian and Swabian Jurassic successions. The rocks commonly include marine limestone and marl deposited on an extensive carbonate shelf.
These sediments accumulated under changing seabed conditions. Some intervals represent relatively continuous deposition, while others preserve evidence of slower sedimentation, reworking or periods during which shells became concentrated on the seafloor.
Upper Jurassic Sea of Bavaria
During the Lower Kimmeridgian, the region now forming Bavaria lay beneath a warm, shallow sea connected to the wider Tethyan marine realm. The familiar hills, valleys and limestone plateaux of modern southern Germany had not yet developed.
Ammonites moved through the water alongside belemnites and other cephalopods. The seabed supported bivalves, brachiopods, gastropods, echinoids, sponges and numerous burrowing organisms. Their shells and skeletal remains became incorporated into carbonate mud that eventually hardened into limestone and marl.
After this ammonite died, its shell settled onto the seabed. Soft tissues decayed, and sediment entered the body chamber and any damaged internal chambers. Continued burial gradually transformed the surrounding sediment into solid rock.
The original aragonitic shell could dissolve, recrystallise or be replaced by more stable minerals. Sediment hardened within the shell to create a natural internal mould, preserving the ammonite’s spiral form and detailed rib pattern even where the original shell material was later lost.
Kirchberg bei Pappenheim Provenance
Kirchberg bei Pappenheim lies in the Franconian Jura of Bavaria, a region internationally known for its fossiliferous Upper Jurassic rocks. The wider Pappenheim area preserves marine limestones and related sediments deposited within the Jurassic sea that once covered southern Germany.
A fossil retaining such precise locality information has considerably greater geological value than a specimen recorded simply as German or European. Its Kirchberg bei Pappenheim provenance connects it with a particular regional succession, while the Malm Gamma 1 and Platynota Zone details place it within a closely defined interval of Jurassic time.
Authentic Historic Fossil for Collection and Display
This genuine Ataxioceras (Parataxioceras) desmoides desmoides ammonite is an excellent addition to a collection of German fossils, Kimmeridgian ammonites, Bavarian natural-history specimens or historically provenanced fossils.
The combination of ornate ribbing, detailed Lower Kimmeridgian stratigraphy and 1929 collection provenance gives the piece strong geological, historical, educational and display interest. Natural matrix, mineral staining, weathered areas, incomplete shell sections, small fractures and irregular surfaces are authentic characteristics of the specimen.
This is a carefully chosen individual fossil, and the photograph shows the actual specimen you will receive, rather than a representative example.
Full sizing is shown in the photographs.
This fossil is a 100% genuine specimen and includes a generic Certificate of Authenticity card with a lifetime guarantee.
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