Description Sonninia pseudotuberculata Ammonite Fossil – Inferior Oolite Group, Middle Jurassic, Oborne Wood, Dorset This genuine Sonninia pseudotuberculata ammonite fossil is a carefully chosen Middle Jurassic specimen from the Inferior Oolite Group at Oborne Wood, Dorset, UK. Dating to the Bajocian Stage of the Middle Jurassic, within the Laeviuscula Zone, this fossil represents an excellent example of a classic British Jurassic ammonite from one of Dorset’s important inland Inferior Oolite localities. The fossil shown in the photographs is the actual specimen you will receive. Full sizing please see photo. This specimen is supplied with a Certificate of Authenticity lifetime guarantee generic card, confirming that it is a genuine fossil suitable for collectors, educational displays, geological study, natural history cabinets, and fossil gift collections. Fossil Type and Species This specimen is identified as Sonninia pseudotuberculata, an ammonite from the Middle Jurassic seas of southern England. Ammonites were extinct marine cephalopods related to modern squid, cuttlefish, and nautilus. They possessed coiled, chambered shells divided internally into buoyancy chambers, allowing them to move through the water column as active marine predators or scavengers. Sonninia is a well-known Bajocian ammonite genus and is particularly important in Jurassic biostratigraphy. Species within this group are valued by collectors because they combine attractive shell form with strong geological significance. Sonninia pseudotuberculata is associated with the early Bajocian ammonite faunas of the Inferior Oolite Group and is a desirable named species for collectors of British ammonites. Geological Age, Zone and Formation This ammonite comes from the Inferior Oolite Group, a fossil-rich Middle Jurassic rock sequence that is widely exposed in parts of Dorset, Somerset, Gloucestershire, and surrounding areas. The specimen dates to the Bajocian Stage, approximately 170 million years old, and is recorded from the Laeviuscula Zone. The Laeviuscula Zone is an important ammonite biozone within the Lower Bajocian. Ammonite zones are used by geologists to divide Jurassic rocks into highly precise time intervals, because ammonites evolved rapidly and were widely distributed in ancient seas. A fossil with a known ammonite zone has added scientific and collecting interest, as it can be placed more accurately within the Middle Jurassic timeline. The Inferior Oolite Group was deposited in warm, shallow marine conditions. During the Bajocian, this part of what is now Dorset lay beneath a Jurassic sea where carbonate sediments, shell debris, ooids, iron-rich material, and marine fossils accumulated on the sea floor. These deposits preserve a wide range of marine life, including ammonites, bivalves, brachiopods, gastropods, echinoids, corals, and other invertebrates. Location – Oborne Wood, Dorset, UK Oborne Wood in Dorset is a recognised locality for Inferior Oolite fossils and is associated with Middle Jurassic marine strata. Fossils from this area are appreciated for their classic British provenance and their connection to the rich Jurassic geology of southern England. While coastal Dorset localities are often more widely known, inland sites such as Oborne Wood are also important for understanding the development of Jurassic seas across the region. A specimen from Oborne Wood carries strong locality interest for collectors who specialise in Dorset fossils, British ammonites, Inferior Oolite fossils, or Middle Jurassic palaeontology. The combination of a named species, precise geological group, Bajocian age, and Laeviuscula Zone provenance makes this a highly collectable piece. Morphology and Collecting Interest Sonninia ammonites are generally recognised by their coiled planispiral shells, ribbed ornament, and distinctive Jurassic ammonite profile. Depending on preservation, features may include prominent ribbing, whorl curvature, shell compression, and traces of the original chambered structure. These features reflect the animal’s growth pattern and are useful for comparing related ammonites within the Sonniniidae. The species name pseudotuberculata refers to a form associated with ornament that may appear tuberculate or strongly sculptured in suitable preservation. This makes the fossil especially interesting to collectors who appreciate ammonites with defined shell architecture and visible morphological character. Authenticity and Display All of our fossils are 100% genuine specimens and come with a Certificate of Authenticity. This Sonninia pseudotuberculata ammonite has been carefully selected for its geological interest, named identification, and desirable Dorset provenance. The photograph shows the actual specimen you will receive, making it suitable for collectors who want a clearly represented fossil for display or study. This genuine Middle Jurassic ammonite fossil from the Inferior Oolite Group at Oborne Wood, Dorset, is an attractive and scientifically interesting addition to any fossil collection, especially for collectors of British ammonites, Jurassic Coast geology, Dorset fossils, and Bajocian marine life.
