Description
Arnioceras Fossil Ammonite and Bivalve from Black Ven, Lyme Regis
This genuine Arnioceras fossil ammonite with associated bivalve comes from the Black Ven Marls of the Lower Lias, collected from Black Ven, Lyme Regis, Dorset, on the famous Jurassic Coast of the UK. It is a carefully chosen fossil specimen, supplied with a Certificate of Authenticity lifetime guarantee generic card. Full sizing can be seen in the photo, and the image shows the actual specimen you will receive.
Your specimen was discovered by our own team members, Alister and Alison, and has been cleaned, prepped and treated by Alison. This makes it a particularly appealing fossil for collectors who value genuine British material with known provenance. Black Ven is one of the most important and historic fossil localities in the UK, celebrated for its Lower Jurassic marine fossils, including ammonites, bivalves, belemnites and occasional marine reptile remains.
Species and Scientific Interest
Arnioceras is a classic Lower Jurassic ammonite genus, best known for its elegant, evolute shell form and strong, regular ribbing. Ammonites were extinct marine cephalopods related to modern squid, cuttlefish and nautilus. They lived in ancient seas and are among the most important fossils used for dating Jurassic rocks because many species evolved rapidly and were widely distributed.
Arnioceras is generally associated with the Sinemurian Stage of the Lower Jurassic, making specimens from this type of deposit approximately 190 to 199 million years old. The genus is commonly placed within the family Arietitidae, superfamily Psiloceratoidea, order Ammonitida. Its distinctive shell form, with open coiling and prominent ribs, makes it a highly recognisable ammonite for collectors of British Jurassic fossils.
The associated bivalve adds further palaeontological interest to this specimen. Bivalves were shelled marine molluscs that lived on or within the ancient sea floor. Their presence alongside the ammonite helps illustrate the diverse marine ecosystem that existed in the Lyme Regis area during the Early Jurassic.
Black Ven Marls and Lower Lias Geology
The Black Ven Marls are part of the Lower Lias sequence exposed around Lyme Regis and Charmouth on the Dorset coast. These beds consist mainly of dark clays, marls and limestone horizons deposited in a shallow marine environment. During the Early Jurassic, this region was covered by warm epicontinental seas, where fine sediment settled on the sea floor and preserved a rich fossil record.
The Lower Lias is especially important for ammonite biostratigraphy. Fossils such as Arnioceras help palaeontologists divide the Jurassic rock sequence into zones and subzones, allowing different exposures to be correlated across Britain and Europe. Ammonites from these beds are therefore valued not only as attractive fossils, but also as scientifically significant guide fossils.
Locality: Black Ven, Lyme Regis, Dorset
Black Ven is a famous fossil-bearing cliff and landslip system situated between Lyme Regis and Charmouth. It forms part of the UNESCO World Heritage Jurassic Coast, a coastline internationally recognised for its outstanding geological record. Erosion of the cliffs continually reveals fossils from the Lower Jurassic strata, making the area one of the most productive and historically important fossil localities in Britain.
The Lyme Regis area has a long association with fossil collecting and early palaeontology. It became world-famous through the discoveries of Mary Anning and remains one of the best-known fossil locations in the world. Specimens from Black Ven are highly collectable because they combine classic British geology, historic locality importance and strong visual appeal.
Morphology and Display Features
Arnioceras ammonites are admired for their neat coiled shape, regular ribbing and attractive natural symmetry. The ribs form part of the original shell ornamentation and would have strengthened the shell during life. Depending on preservation, specimens from the Black Ven Marls may show grey, cream, brown or iron-rich tones, natural matrix, raised rib detail and contrasting fossil surfaces.
The bivalve association gives this specimen additional display character and makes it more than a single-species fossil. It represents a small snapshot of the Lower Jurassic sea floor, preserving more than one type of marine organism in the same piece. This makes it ideal for collectors who appreciate fossil associations, natural matrix specimens and educational examples of ancient marine life.
Authenticity and Collector Appeal
This Arnioceras fossil ammonite with bivalve is a genuine Lower Jurassic specimen from Black Ven, Lyme Regis, Dorset, UK. It includes a Certificate of Authenticity lifetime guarantee generic card, giving confidence to fossil collectors, geology enthusiasts, students and gift buyers.
With its classic Jurassic Coast provenance, attractive ammonite form, associated bivalve and carefully prepared presentation, this fossil would make an excellent addition to a British fossil collection, ammonite display, educational geology collection or Lyme Regis fossil suite.
Reviews
There are no reviews yet.