Fossil Ammonite Gulielmiceras gulielmii Jurassic Callovian Newbold Quarry Hull UK

Description

Authentic Jurassic Ammonite – Gulielmiceras gulielmii

Presented here is a genuine ammonite fossil of the species Gulielmiceras gulielmii from the Lower Callovian stage of the Jurassic period, collected from the Kellaways Formation at Newbold Quarry, Hull, Yorkshire, United Kingdom. This remarkable specimen, dating back approximately 165 million years, is an outstanding example of a rare ammonite preserved in the clay and marl sediments of northern England. The photographs show the exact fossil you will receive, alongside a 1cm scale cube for accurate sizing. Every fossil is supplied with a Certificate of Authenticity, guaranteeing its provenance and scientific integrity.

Geological Context – The Kellaways Formation

This ammonite originates from the Kellaways Formation, a unit of the Lower Callovian stage (Middle Jurassic, ~165 million years ago). The Kellaways Clay and underlying sandy deposits formed in shallow marine environments when warm epicontinental seas covered large parts of Britain. These calm, muddy seabeds were particularly favourable for fossil preservation, capturing a wide diversity of ammonites, bivalves, and marine reptiles.

Newbold Quarry, Hull, is a classic locality that has yielded scientifically important ammonite specimens, particularly those belonging to the genera Kosmoceras, Reineckia, and Gulielmiceras. These fossils are essential for refining the biostratigraphy of the Callovian, as each ammonite species can be tied to specific time intervals.

Scientific Classification

• Kingdom: Animalia
• Phylum: Mollusca
• Class: Cephalopoda
• Order: Ammonitida
• Superfamily: Stephanoceratoidea
• Family: Stephanoceratidae
• Genus: Gulielmiceras
• Species: Gulielmiceras gulielmii

This taxonomic placement emphasises the species’ evolutionary connection to other robust and heavily ornamented ammonites of the Middle Jurassic seas.

Morphological Features of Gulielmiceras gulielmii

The ammonite Gulielmiceras gulielmii is distinguished by:

• Strongly ribbed shell, with bold primary ribs branching into finer secondary ribs across the whorls.
• Thick, evolute shell structure, where earlier coils remain visible, giving the fossil a striking aesthetic.
• Suture complexity, with intricate lobes and saddles typical of Callovian ammonites.
• Robust ornamentation, reflecting adaptation to the hydrodynamic conditions of Jurassic seas.

These features made the species highly recognisable to paleontologists and also valued by collectors for its bold visual appeal.

Palaeoecology – Life in the Jurassic Seas

Ammonites such as Gulielmiceras gulielmii were nektonic cephalopods, freely swimming in the open seas. They used their chambered shells to regulate buoyancy while preying upon smaller marine organisms such as plankton, fish fry, and crustaceans. Their abundance and diversity reflect a thriving marine ecosystem in the Callovian seas.

This species also serves as an index fossil, useful for dating and correlating Jurassic strata across different regions of Europe. Its presence in the Kellaways Formation is of particular importance for refining the Callovian biozones.

Collector and Scientific Value

This specimen is both aesthetic and scientifically significant, representing a species essential to Jurassic ammonite stratigraphy. Fossils of Gulielmiceras gulielmii are highly sought after by collectors due to their rarity and their striking ribbed morphology.

Owning this ammonite means holding a piece of Yorkshire’s deep geological past, a fossil that not only displays beautifully but also has a place in the story of Earth’s history.

Provenance and Guarantee

• Species: Gulielmiceras gulielmii
• Age: Jurassic, Lower Callovian (~165 million years old)
• Formation: Kellaways Formation
• Locality: Newbold Quarry, Hull, Yorkshire, United Kingdom

This fossil is guaranteed authentic, photographed as the exact specimen offered, and accompanied by a Certificate of Authenticity.

This rare Jurassic ammonite, Gulielmiceras gulielmii from the Kellaways Formation of Yorkshire combines striking natural beauty with important scientific context, making it a valuable acquisition for both collectors and researchers.