Description
Genuine Dorsetensia liostraca subtecta Ammonite Fossil
This listing is for a genuine Dorsetensia liostraca subtecta ammonite fossil from the Inferior Oolite Group at Oborne Wood, Dorset, UK. Dating from the Bajocian Stage of the Middle Jurassic, specifically the Romani Subzone, this specimen represents a carefully labelled British Jurassic ammonite from one of southern England’s classic fossil-bearing marine deposits.
Dorsetensia ammonites are highly collectible Middle Jurassic cephalopods, appreciated for their attractive coiled shell form, scientific value, and close connection with the ammonite biostratigraphy of the Inferior Oolite Group. This fossil is a carefully chosen piece, and the photograph shows the actual specimen you will receive. Full sizing can be seen in the photo.
Geology, Age and Dorset Locality
This ammonite comes from the Inferior Oolite Group, a major Middle Jurassic geological unit exposed across parts of Dorset and southern England. The Inferior Oolite consists of limestones, sandy limestones, marls, shell-rich beds, iron-rich horizons, and oolitic sediments that were deposited in warm, shallow marine environments.
The fossil is Bajocian in age, approximately 170 to 168 million years old. The Bajocian was an important interval in ammonite evolution, with many distinctive ammonite groups diversifying across the shallow shelf seas of Europe. Ammonites from this stage are especially valuable to geologists because their rapid evolution allows Jurassic rock layers to be divided into detailed zones and subzones.
Oborne Wood and the Romani Subzone
Oborne Wood, near Sherborne in Dorset, is associated with fossil-bearing Middle Jurassic deposits of the Inferior Oolite Group. Fossils from this locality are highly regarded by collectors of British ammonites because they preserve part of the rich marine fauna that lived in the warm Jurassic seas of southern England.
This specimen is recorded from the Romani Subzone, a refined ammonite biostratigraphic division within the Bajocian. Subzones are used by palaeontologists to identify narrower intervals of geological time based on characteristic ammonite faunas. A fossil with this level of stratigraphic detail is especially desirable for collectors who value precise geological provenance and scientifically meaningful labelling.
The Romani Subzone is associated with important Bajocian ammonite successions, including forms such as Dorsetensia and related sonniniid ammonites. This makes the specimen not only an attractive fossil for display but also a useful example of how ammonites help date and correlate Middle Jurassic marine rocks.
Fossil Type and Species Details
Dorsetensia liostraca subtecta was an ammonite, an extinct marine mollusc belonging to the cephalopod group. Ammonites are related to modern squid, cuttlefish, octopus, and nautilus, although ammonites themselves became extinct at the end of the Cretaceous Period. Like other ammonites, Dorsetensia had a coiled external shell divided internally into chambers. The living animal occupied the final body chamber, while the earlier chambers helped control buoyancy as it moved through the Jurassic sea.
The genus Dorsetensia is a characteristic Middle Jurassic ammonite group named from Dorset and strongly linked with Bajocian marine faunas. Dorsetensia ammonites typically show planispiral coiling, defined whorl development, and ornament that may vary from smoother shell forms to more visibly ribbed examples depending on species, growth stage, and preservation. The name liostraca is associated with a smoother shell character, while subtecta represents a more specific form within this labelled taxon.
Scientific classification places Dorsetensia within Phylum Mollusca, Class Cephalopoda, Subclass Ammonoidea, Order Ammonitida, Superfamily Hammatoceratoidea, and Family Sonniniidae. Features such as whorl shape, ribbing strength, shell compression, and suture pattern are important in identifying ammonites of this group.
Middle Jurassic Marine Environment
During the Bajocian, the area now known as Dorset lay beneath warm, shallow seas on the margin of an ancient European marine shelf. The Inferior Oolite Group records these conditions through carbonate-rich sediments, oolitic limestones, sandy beds, marine muds, and shell-rich layers.
Dorsetensia liostraca subtecta would have lived within this marine environment as part of a diverse Jurassic ecosystem. The same seas supported belemnites, bivalves, brachiopods, gastropods, echinoids, crustaceans, fish, and marine reptiles. Ammonites were active members of this marine food web, using their chambered shells for buoyancy control while moving through the water column.
Collectible British Jurassic Ammonite
This Dorsetensia liostraca subtecta ammonite fossil is an excellent specimen for collectors interested in British fossils, Dorset geology, Middle Jurassic ammonites, Inferior Oolite fossils, Bajocian biostratigraphy, and scientifically labelled natural history specimens. Its Oborne Wood locality, Romani Subzone attribution, named taxon, and classic ammonite form give it strong collector, display, and educational appeal.
This fossil is a genuine specimen and includes a Certificate of Authenticity lifetime guarantee generic card. The photograph shows the actual fossil you will receive, making this a carefully selected and accurately represented specimen from the Middle Jurassic marine deposits of Oborne Wood, Dorset, UK.
Reviews
There are no reviews yet.