Description
Rare Orthodactylioceras directum Fossil Ammonite
This is a rare and carefully chosen Orthodactylioceras directum fossil ammonite from the Toarcian stage of the Jurassic Period, collected from Lyme Regis, Dorset, United Kingdom. Lyme Regis is one of the most famous fossil localities in Britain and forms part of the world-renowned Jurassic Coast, a region celebrated for its ammonites, marine reptiles, belemnites and other prehistoric marine fossils.
This fossil is a genuine specimen and includes a Certificate of Authenticity lifetime guarantee generic card. Full sizing can be seen in the photograph, and the photo shows the actual specimen you will receive. This makes it an excellent choice for collectors who want to view the exact preservation, shape, surface texture, colour and natural character of the fossil before purchase.
Geology and Jurassic Age
Orthodactylioceras directum dates from the Toarcian stage of the Early Jurassic, approximately 183 to 174 million years old. During this time, the area now known as Dorset was covered by warm Jurassic seas. Fine marine muds, silts and limestones accumulated across the seabed, preserving the remains of ammonites, belemnites, bivalves, fish, crinoids and marine reptiles.
The Toarcian is an important stage in Jurassic geology because ammonites from this interval are widely used as index fossils. Their rapid evolution and broad distribution allow palaeontologists and geologists to date and correlate marine rock layers with impressive precision. Fossils from the Toarcian of the Dorset coast provide a fascinating window into ancient marine ecosystems that existed long before modern seas, mammals or flowering plants.
Fossil Type and Species
This specimen is an ammonite, an extinct marine cephalopod related to modern squid, cuttlefish and nautilus. Ammonites lived inside coiled, chambered shells. The animal occupied the outer body chamber, while the earlier chambers helped regulate buoyancy, allowing it to move through the water column in search of food and safety.
Species: Orthodactylioceras directum
Genus: Orthodactylioceras
Family: Dactylioceratidae
Superfamily: Eoderoceratoidea
Order: Ammonitida
Class: Cephalopoda
Phylum: Mollusca
Orthodactylioceras is part of the dactylioceratid ammonite group, a distinctive family of Early Jurassic ammonites known for their evolute coiling and ribbed shells. These ammonites are highly collectable because they combine classic ammonite geometry with strong biostratigraphic importance.
Morphology and Identification Features
Orthodactylioceras directum displays the classic coiled ammonite form that makes these fossils instantly recognisable. Dactylioceratid ammonites are typically evolute, meaning the inner whorls remain visible rather than being tightly enclosed by later growth. This open spiral form gives the fossil strong visual appeal and clearly shows the natural growth pattern of the shell.
The shell ornament often includes regular ribbing across the whorls, a feature that helped strengthen the shell and is important for fossil identification. The balanced spiral, visible whorl structure and natural surface detail make this specimen suitable for display in a fossil cabinet, educational collection, geology display or natural history setting.
Lyme Regis, Dorset Fossil Locality
Lyme Regis is one of the most historic fossil collecting areas in the United Kingdom. The cliffs and foreshore around Lyme Regis have produced many important Jurassic fossils and are closely associated with the early history of palaeontology. Fossils from this area are popular with collectors because they carry both scientific value and classic British locality appeal.
The marine deposits around Lyme Regis were formed in ancient seabed environments where shells and bones could be buried in sediment and preserved over millions of years. The resulting fossils often show natural mineralisation, matrix, surface texture and colour variation, all of which add to their individual character.
Authenticity and Collector Appeal
This Orthodactylioceras directum fossil ammonite is a genuine specimen and includes a Certificate of Authenticity lifetime guarantee generic card. The fossil has been carefully chosen as a quality collector’s piece, and the photograph shows the exact specimen supplied.
As with all genuine fossils, natural cracks, mineralisation, matrix, surface marks, preparation marks, colour variation and age-related wear may be present. These features are normal characteristics of authentic fossils and form part of the specimen’s geological history. This rare Toarcian ammonite from Lyme Regis, Dorset is ideal for collectors of British fossils, Jurassic ammonites, Dorset fossils, natural history specimens and scientifically interesting marine fossils from one of the UK’s most iconic fossil localities.
