Graphoceras Ludwigella rudis Ammonite Fossil Aalenian Dorset UK Genuine COA – Inferior Oolite Beaminster Jurassic Specimen

Description

Genuine Graphoceras (Ludwigella) rudis Ammonite Fossil

This carefully selected fossil is an authentic Graphoceras (Ludwigella) rudis ammonite from the Inferior Oolite Group of Beaminster, Dorset, UK. Dating from the Aalenian Stage of the Middle Jurassic, it represents a marine animal that lived in the seas covering southern Britain approximately 174–170 million years ago.

The photograph shows the actual fossil specimen you will receive, allowing you to examine its preservation, natural colouration and individual geological characteristics before purchasing. Full sizing and scale information can be seen in the accompanying photographs.

Aalenian Jurassic Geology of Dorset

The specimen originates from the fossil-rich Inferior Oolite succession around Beaminster in west Dorset. These rocks were deposited during the early Middle Jurassic, when the region formed part of a warm, shallow marine environment situated along the margins of an extensive European sea.

The Inferior Oolite Group is well known for its richly fossiliferous limestones, marls and iron-rich beds. Sediment accumulated across a variable sea floor influenced by changing water depth, currents, periods of erosion and episodes of reduced sedimentation. These conditions produced condensed fossil horizons in which ammonites and other marine organisms could become concentrated.

Ammonites preserved within these deposits are particularly valuable because their relatively rapid evolution and widespread geographical distribution allow individual rock layers to be compared and dated. Fossils from the Aalenian succession therefore provide both attractive collectable specimens and important evidence for reconstructing the geological history of Jurassic Dorset.

Ammonite Form and Natural Features

Graphoceratid ammonites are generally recognised by their planispirally coiled shells, compressed whorl profiles and streamlined overall appearance. The shell of a living ammonite was divided internally into chambers. The animal occupied the final body chamber, while the older chambers formed the phragmocone and were used to help control buoyancy within the water column.

Members associated with Ludwigella commonly display an evolute to moderately involute shell form, with earlier whorls remaining partly visible around the central umbilicus. Fine to moderately developed ribs may sweep across the flanks towards the outer edge of the shell, while the venter can become relatively narrow or sharpened. The precise appearance varies according to growth stage, preservation and the degree to which the original shell has been replaced or embedded within the surrounding rock.

Any small fractures, incomplete areas, mineral-filled sections, surface wear or attached matrix are natural characteristics of a genuine Jurassic fossil. These features reflect the specimen’s burial, mineralisation and recovery from its host rock and help distinguish it as an individual geological object rather than a manufactured replica.

Scientific Classification

Fossil type: Ammonite

Scientific name: Graphoceras (Ludwigella) rudis

Family: Graphoceratidae

Superfamily: Hammatoceratoidea

Order: Ammonitida

Geological group: Inferior Oolite Group

Geological stage: Aalenian, Middle Jurassic

Locality: Beaminster, Dorset, United Kingdom

Ammonites belonged to an extinct group of marine cephalopods related to living squid, cuttlefish, octopuses and nautiluses. They were highly successful predators and scavengers throughout much of the Mesozoic Era, developing a wide variety of shell forms before becoming extinct at the end of the Cretaceous Period.

Collectable Dorset Fossil Specimen

This Beaminster ammonite would make an excellent addition to a collection of British fossils, Dorset fossils, Jurassic ammonites, Inferior Oolite fossils or scientifically identified palaeontological specimens. Its documented species, locality and geological age also make it suitable for educational displays, natural history collections, office décor or a distinctive gift for a fossil enthusiast.

The fossil is supplied as a 100% genuine specimen and includes a Certificate of Authenticity generic card with a lifetime guarantee. The specimen has been individually chosen for its collectable qualities, and the listing photographs show the exact piece that will be supplied.

Full sizing please see photo.