This listing is for a genuine Amaltheus striatus Fossil Ammonite, collected from the famous Jurassic coastline of Runswick Bay, Whitby, United Kingdom. This striking specimen dates to the Middle Lias (Lower Jurassic), approximately 180 million years ago, and is an excellent representation of one of Whitby’s classic ammonite species. Every fossil we offer is carefully selected, photographed individually, and supplied with a Certificate of Authenticity, ensuring that you receive the exact specimen shown.
The specimen originates from the Jurassic Period, specifically the Middle Lias, Lower Jurassic, within the Pliensbachian stage. The ammonite-rich deposits at Runswick Bay and Whitby have been celebrated since the 19th century for their abundance and preservation. These shales and concretions formed in shallow marine environments where fine muds rapidly covered marine organisms, preserving them in remarkable detail. Fossils from this locality are internationally renowned for their scientific importance and remain highly desirable to collectors.
This specimen belongs to the species Amaltheus striatus, a member of the family Amaltheidae, superfamily Eoderoceratoidea, and order Ammonitida. Ammonites were marine cephalopods related to squids and octopuses, using their chambered shells for buoyancy control. Amaltheus striatus is an iconic ammonite of the Jurassic seas, notable for its distinctive ribbing and compressed shell form. This species is widely recognised as an important index fossil, aiding geologists in identifying the Amaltheus striatus Biozone within the Lower Jurassic stratigraphic framework.
The shell of Amaltheus striatus is characterised by several key features:
These morphological features not only distinguish Amaltheus striatus but also provide paleontologists with key evidence for stratigraphic dating. For collectors, the fine ribbing and elegant coiling make it an aesthetically pleasing specimen.
The Amaltheus striatus Zone is one of the most important ammonite zones of the Lower Jurassic Pliensbachian stage. The widespread presence of this species across Europe makes it a highly reliable index fossil. Owning such a specimen provides a direct connection to a fossil used extensively in international stratigraphy and geological research. Its presence alongside other Jurassic fauna demonstrates the biodiversity of the ancient Whitby seas.
During the Early Jurassic, Whitby and Runswick Bay were submerged beneath a shallow marine basin. Fine sediments were deposited on the seafloor, entombing marine life soon after death. In some cases, low-oxygen conditions limited scavenging and decay, resulting in exceptional fossil preservation. Ammonites like Amaltheus striatus would have lived as active swimmers, preying on smaller marine creatures before becoming part of the fossil record that defines these world-famous cliffs.
Whitby ammonites are among the most recognisable fossils in the world. They were collected extensively during the Victorian era, admired for both their scientific and decorative qualities. Today, fossils such as Amaltheus striatus remain highly sought after by collectors for their historical importance, aesthetic appeal, and contribution to paleontology.
This beautifully preserved Amaltheus striatus ammonite is a rare and scientifically significant fossil from Whitby’s Jurassic coast. A perfect addition to any fossil collection, it represents both natural history and the enduring legacy of Britain’s most famous fossil locality.