Very Rare Echioceras Ammonite Fossil Lower Lias Jurassic Bristol Somerset UK – Genuine British Ammonite with Hand Signed Certificate

Description Very Rare Echioceras Ammonite from the Jurassic of Somerset This exceptional Echioceras ammonite fossil originates from the Lower Lias deposits at St Peter’s Field, Bristol, Somerset, United Kingdom, a historically important Jurassic fossil locality. Dating to the Early Jurassic Period approximately 190–200 million years ago, this rare ammonite represents an extinct marine cephalopod that once thrived in the ancient seas covering much of what is now southern Britain. Specimens from this locality are highly desirable due to their rarity and the quality of preservation found within the Lower Lias strata. The fossil displayed in the photographs is the exact specimen you will receive, carefully selected for its scientific interest and visual appeal. This fossil includes a fully hand-signed Premium Certificate of Authenticity, confirming that the specimen is a genuine natural fossil. Please refer to the photographs for full specimen sizing and scale. About Echioceras – Early Jurassic Ammonite Cephalopod Echioceras is a well-known genus of ammonite from the Early Jurassic seas. These marine molluscs belonged to the same broader cephalopod group as modern squid, cuttlefish, and octopus, although ammonites possessed an external spiral shell divided internally into chambers. Taxonomic classification: Phylum: Mollusca Class: Cephalopoda Subclass: Ammonoidea Order: Ammonitida Superfamily: Eoderoceratoidea Family: Echioceratidae Genus: Echioceras The genus Echioceras is particularly significant in stratigraphy because it is associated with the Echioceras raricostatum Biozone, an important ammonite biozone used by geologists to identify specific intervals of the Lower Jurassic Pliensbachian Stage. The genus was formally described by John Phillips, a pioneering British geologist and palaeontologist who made major contributions to the understanding of Jurassic fossil faunas in Britain. Geological Setting – The Lower Lias Formation This ammonite was discovered in the Lower Lias, a sequence of marine limestones and shales deposited during the Early Jurassic when much of the United Kingdom lay beneath a warm shallow sea. These sediments accumulated on the seabed where fine mud and carbonate material slowly buried marine organisms after death. The Lower Lias is particularly famous for preserving a rich marine ecosystem including: Ammonites Belemnites Bivalves and gastropods Marine reptiles such as ichthyosaurs and plesiosaurs Crinoids and other echinoderms The sedimentary conditions of the Lower Lias allowed delicate shell structures to fossilise, often preserving fine surface details that help palaeontologists identify species and study their evolutionary relationships. Shell Morphology and Fossil Characteristics The shell of Echioceras forms a classic ammonite spiral known as a planispiral coil, where the whorls expand outward while remaining tightly wound around the centre. Internally the shell is divided into chambers separated by curved walls known as septa, which form intricate suture patterns where they meet the outer shell. Characteristic features of Echioceras ammonites include: Moderately evolute shell coiling with visible inner whorls Fine ribbing extending across the flanks of the shell Distinct growth lines marking stages of shell expansion Rounded whorl sections typical of many early Jurassic ammonites These ribbed shells provided structural strength while the internal chambers allowed the living animal to control buoyancy, enabling it to move efficiently through the water column while hunting small marine organisms. A Rare British Fossil with Premium Certificate This specimen represents a very rare ammonite from a classic British Jurassic locality, making it a valuable addition to any fossil collection, geological display, or educational collection. Key features include: Genuine Echioceras ammonite fossil Very rare specimen from St Peter’s Field Geological formation: Lower Lias Age: Early Jurassic Locality: St Peter’s Field, Bristol, Somerset, UK Clear ammonite spiral morphology The exact specimen shown in the photographs Includes a fully hand-signed Premium Certificate of Authenticity Ammonites such as Echioceras are among the most important fossils for understanding the evolutionary history of Jurassic marine life. Their rapid evolution and distinctive shell forms allow scientists to precisely date rock layers, making them one of the most significant index fossils in palaeontology. This remarkable specimen offers a genuine connection to the ancient Jurassic seas that once covered Britain nearly 200 million years ago, preserving the elegant spiral shell of a long-extinct marine predator that once inhabited those waters.