#ammonite bivalve combo fossil

[uk-fossils]

Leioceras Ammonite & Lima gigantea Bivalve Fossil Block – Jurassic Coast, Burton Bradstock, Dorset – Inferior Oolite – Genuine with COA

Leioceras Ammonite & Lima gigantea Bivalve Fossil – A Unique Jurassic Pair

This rare fossil block contains both a beautifully preserved Leioceras ammonite and a large Lima gigantea bivalve, both naturally associated within the same matrix. Collected from the iconic Burton Bradstock site on the Jurassic Coast of Dorset, UK, this piece represents an exceptional snapshot of Jurassic marine life.

Fossil & Geological Information:

Ammonite Genus: Leioceras

Family: Leioceratidae

Superfamily: Hildoceratoidea

Order: Ammonitida

Morphological Features: Smooth, involute shell with faint ribbing, rounded venter

Notable: Commonly used as an index fossil for the Middle Jurassic; streamlined shape suggests active nektonic life

Bivalve Species: Lima gigantea

Family: Limidae (File Clams)

Morphology: Large, strongly ribbed shell with radial ornamentation; known for living partially buried in soft sediment with a large muscular foot

Ecology: Epifaunal and filter-feeding organism

Geological Formation: Inferior Oolite

Stratigraphy: Middle Jurassic, Bajocian Stage (~170–168 million years ago)

Location: Burton Bradstock, Dorset, UK (Jurassic Coast UNESCO World Heritage Site)

Depositional Environment: Shallow, warm epicontinental sea with high biodiversity and carbonate sedimentation

Biozone (Inferred): Leioceras opalinum Zone, a key ammonite biozone of the Bajocian Stage

Specimen Details:

Block Size: Please see scale cube (1cm) in the photo for accurate dimensions

Discovery Date: 17 January 2025

Collected By: Alister and Alison, UKGE Team

Preparation: Professionally cleaned, consolidated and treated by Alison for optimal preservation

Photograph: What you see is what you get – actual specimen shown

Authenticity: Comes with a Certificate of Authenticity from UKGE

Scientific and Collector Relevance:

This fossil block not only features two distinct and well-known Jurassic marine taxa, but it also serves as a mini-ecosystem representation of life in the Bajocian seas. Such natural combinations are uncommon and highly prized by collectors, educators, and palaeontology enthusiasts.

Perfect For:

Fossil collectors, museum-quality displays, educational settings, or as a unique natural history gift. A wonderful opportunity to own a dual fossil specimen from one of the UK’s most fossiliferous formations.