Dactylioceras commune Fossil Ammonite Jurassic Whitby Runswich Bay UK Middle Lias

Description

Authentic Dactylioceras commune Fossil Ammonite from Whitby, UK

This listing offers a genuine Dactylioceras commune ammonite fossil from the Middle Lias (Lower Jurassic) strata of Runswick Bay, Whitby, North Yorkshire, United Kingdom. The fossil displayed in the photographs is the exact specimen you will receive, chosen for its quality and preservation. As with all of our specimens, this piece is supplied with a Certificate of Authenticity to guarantee its provenance and genuineness.

Geological Age and Context

This ammonite dates to the Lower Jurassic, Toarcian Stage, approximately 180–174 million years ago. The exposures along the Yorkshire Coast at Whitby and Runswick Bay are globally recognised as classic fossil localities, yielding ammonites, belemnites, marine reptiles, and fish. These fossils were preserved in fine-grained shales and nodules formed in low-oxygen seabed conditions within a shallow epicontinental sea. Such environments allowed exceptional preservation, often retaining fine details of shell ornamentation.

Scientific Classification

• Species: Dactylioceras commune
• Genus: Dactylioceras
• Family: Dactylioceratidae
• Superfamily: Eoderoceratoidea
• Order: Ammonitida
• Class: Cephalopoda
• Age: Middle Lias, Lower Jurassic (Toarcian)
• Locality: Runswick Bay, Whitby, North Yorkshire, UK

Morphological Features

Dactylioceras commune is one of the best-known ammonites of the Whitby area and is easily distinguished by its:

• Strongly ribbed, planispiral shell with whorls that remain tightly coiled.
• Thick, well-developed ribs radiating across the flanks and extending cleanly over the venter.
• More robust form compared with related species such as Dactylioceras tenuicostatum, giving it a bolder appearance.
• A keel that improved hydrodynamics, reflecting the ammonite’s adaptation as a free-swimming predator in the open seas of the Early Jurassic.

The shell ornamentation of D. commune is particularly striking, and specimens like this one are prized both by collectors and by palaeontologists studying Jurassic biostratigraphy.

Stratigraphic and Biozone Importance

Dactylioceras commune is widely recognised as an index fossil for the Toarcian Stage. Its abundance and distinctive morphology make it extremely valuable for correlating rock layers across Europe and beyond. By identifying layers containing D. commune, geologists can precisely date strata, making it a critical tool in Jurassic stratigraphy.

Depositional Environment

During the Early Jurassic, the region that is now Whitby lay beneath a shallow tropical sea. Warm waters, combined with occasional episodes of reduced oxygen levels, created ideal conditions for fossil preservation. Ammonites such as Dactylioceras commune thrived in these seas, living as active nektonic predators feeding on small crustaceans and other marine life. When they died, their shells settled onto the seabed, where they were rapidly buried and preserved in the soft sediments that later became the Whitby shales.

Collector’s Significance

This specimen of Dactylioceras commune is a classic Whitby ammonite, representing one of the most recognisable fossils of the Jurassic Coast. Its bold ribbing and robust form make it visually striking, while its scientific importance as a stratigraphic marker adds value to any serious fossil collection. These ammonites are highly sought after by collectors worldwide due to their abundance in Whitby and their pivotal role in palaeontology.

Item Details

• Fossil Type: Ammonite – Dactylioceras commune
• Age: Middle Lias, Lower Jurassic (approx. 180–174 million years)
• Location: Runswick Bay, Whitby, United Kingdom
• Condition: Well-preserved, showing strong ribbing and characteristic coiling
• Scale: Rule squares/cube = 1 cm (see photographs for full sizing)
• Certificate: Supplied with a Certificate of Authenticity
• Specimen Shown: The exact fossil in the photographs is the one supplied

A true Dactylioceras commune ammonite fossil from the Jurassic of Whitby – a timeless piece of natural history, combining geological heritage, beauty, and scientific value. An excellent addition to any fossil collection or as a striking display piece.