Description
Genuine Euaspidoceras hypselum Ammonite Fossil
This genuine ammonite fossil is identified as Euaspidoceras hypselum and originates from Sengenthal in Bavaria, Germany. It dates from the Oxfordian Stage of the Upper Jurassic and represents an extinct marine cephalopod that inhabited the seas covering southern Germany more than 150 million years ago.
Euaspidoceras ammonites are recognised for their robust shells, prominent ornamentation and distinctive tubercles. These strongly sculptured features make them particularly attractive examples of Jurassic ammonite evolution and highly desirable additions to collections of German fossils, European ammonites and prehistoric marine life.
This carefully chosen fossil is the exact specimen shown in the listing photographs. Its natural shell form, ornamentation, colour, matrix and individual state of preservation can therefore be examined before purchase. Full sizing and scale information are provided in the photographs.
Species and Scientific Classification
Euaspidoceras hypselum belongs to an advanced group of strongly ornamented Jurassic ammonites. Its broad scientific classification includes:
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Superfamily: Aspidoceratoidea
Family: Aspidoceratidae
Genus: Euaspidoceras
Species: Euaspidoceras hypselum
Ammonites were marine molluscs related to living squid, cuttlefish, octopuses and nautiluses. They possessed externally chambered shells and were among the most successful and diverse animals in Mesozoic marine ecosystems.
The genus Euaspidoceras is recorded from Jurassic marine deposits across several regions, including Germany, France, Britain, Italy, Spain, India and Madagascar, demonstrating the broad distribution of this ammonite lineage within ancient seas.
Distinctive Euaspidoceras Morphology
Euaspidoceras typically possessed a substantial planispiral shell, meaning that its whorls developed within a single plane. The coiling was commonly evolute to moderately involute, leaving at least part of the earlier whorls visible around the central umbilicus.
One of the most recognisable features of the genus is its powerful ornamentation. Strong ribs extend across the shell flanks and may connect prominent rows of tubercles. These tubercles were originally raised projections and, in some individuals, may have supported longer spines during life.
Two principal rows of tubercles may occur, with one positioned closer to the umbilical region and another nearer the outer part of the flank. Their size, spacing and prominence could change as the ammonite matured. The combination of robust ribbing, paired tubercles and a thick shell profile helped produce the characteristic armoured appearance associated with aspidoceratid ammonites.
The precise features visible on this specimen depend upon its growth stage and preservation. It may retain areas of original shell material, mineral replacement, an internal mould or a combination of these forms. Naturally worn tubercles or incomplete projections are expected because prominent shell ornament was especially vulnerable to damage before burial and during later geological exposure.
Chambered Shell and Buoyancy
Internally, the ammonite shell was divided by curved partitions called septa. These formed a sequence of chambers connected by a narrow tube known as the siphuncle. The animal occupied only the final and largest body chamber, while the abandoned earlier chambers contributed to buoyancy regulation.
Where the septa met the exterior shell wall, they produced intricate patterns called suture lines. These structures are important in ammonite classification and help palaeontologists distinguish between different evolutionary groups.
The living animal would have extended its head, eyes and muscular arms from the shell aperture. Its chambered shell provided protection and buoyancy, allowing it to occupy the Jurassic water column alongside other cephalopods, fish and marine reptiles.
Oxfordian Upper Jurassic Age
This fossil comes from the Oxfordian Stage of the Upper Jurassic. The Oxfordian followed the Callovian and preceded the Kimmeridgian, forming an important interval in the development and diversification of Late Jurassic ammonite faunas.
The Sengenthal succession includes fossil-bearing strata extending into the Lower Oxfordian, with scientifically documented ammonite assemblages from the Cordatum Zone. A condensed iron-oolitic and glauconitic bed at the top of the local Sengenthal Formation has produced abundant uncompressed Lower Oxfordian ammonites.
Ammonites are especially valuable to geologists because their shell forms changed relatively rapidly through time. Many species existed for limited geological intervals but were distributed across broad marine areas. Their fossils can therefore be used to date sedimentary rocks and correlate separate exposures.
Jurassic Marine Environment of Bavaria
During the Oxfordian, the region now forming Bavaria lay beneath a warm marine environment. Southern Germany formed part of an extensive system of shallow seas and deeper marine basins connected to the Tethyan Ocean.
These waters supported ammonites, belemnites, nautiloids, bivalves, gastropods, brachiopods, sponges, echinoids, crustaceans, fish and marine reptiles. Carbonate sediment, shell debris, clay and iron-rich material accumulated across the seabed under changing environmental conditions.
Periods of slow sedimentation could produce condensed fossil beds in which shells and other hard remains accumulated over an extended interval. Glauconite and iron-rich ooids found in some Sengenthal deposits are consistent with slow marine deposition, reworking and prolonged exposure of material at or close to the seabed.
Natural Fossilisation and Preservation
After the ammonite died, its shell descended to the Jurassic seabed. Currents, scavenging organisms and sediment movement could damage projecting spines or separate parts of the shell before final burial.
Sediment gradually entered the empty chambers and accumulated around the exterior. As additional deposits built up, pressure compacted the sediment and transformed it into rock. The original aragonitic shell could dissolve, recrystallise or be replaced by other minerals, while hardened sediment preserved the internal shape of the ammonite.
Natural fractures, worn ornamentation, incomplete tubercles, matrix deposits, mineral markings, irregular edges and colour variations are genuine features of fossilisation. They form part of the specimen’s geological history and ensure that every ammonite is completely individual.
Sengenthal, Bavaria Fossil Provenance
Sengenthal, near Neumarkt in Bavaria, became widely known for quarry exposures containing both Middle and Upper Jurassic rocks. The locality attracted fossil collectors for its varied ammonite assemblages and the contrast between darker Middle Jurassic deposits and younger pale calcareous Upper Jurassic strata.
Documented locality information adds considerable scientific and collecting interest. This specimen can be associated with a recognised Upper Jurassic fossil region rather than being offered merely as an unprovenanced decorative ammonite.
Actual Specimen and Certificate of Authenticity
This is a genuine fossil specimen and not a cast, replica or artificial reproduction. The listing photographs show the exact Euaspidoceras hypselum ammonite that will be supplied, allowing you to inspect its shell profile, tubercles, ribbing, matrix, natural colour and individual preservation before purchasing.
Full sizing is shown in the photographs.
The fossil includes a generic Certificate of Authenticity card carrying a lifetime guarantee. Its striking aspidoceratid morphology, Oxfordian age and documented Sengenthal provenance make it an excellent addition to a Jurassic ammonite collection, German fossil display, natural-history cabinet or educational geological collection.
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