Subkossmatia opis Ammonite Fossil Jurassic Madagascar Genuine Authentic COA

Description

Authentic Jurassic Fossil from Madagascar

This beautiful Subkossmatia opis ammonite fossil is a genuine specimen from the Middle Callovian stage of the Jurassic Period, collected in Madagascar. Carefully chosen for its preservation and detail, it is an excellent example of one of the most striking ammonites from this region. The photographs show the actual specimen you will receive, with a 1 cm scale cube for accurate size reference. Each fossil is supplied with a Certificate of Authenticity, ensuring that it is 100% genuine.

Geological Age and Provenance

Dating back approximately 165–163 million years, this ammonite was formed during the Middle Callovian stage of the Jurassic. Madagascar, during this time, was positioned within the southern hemisphere as part of the ancient supercontinent Gondwana. Warm, shallow seas covered much of the region, depositing fine marine sediments that created ideal conditions for fossilisation. The island’s Jurassic deposits are world-renowned for their exceptionally preserved ammonites, making them highly sought after by collectors and paleontologists alike.

Species Identification and Classification

Subkossmatia opis belongs to the class Cephalopoda, order Ammonitida, superfamily Stephanoceratoidea, and family Perisphinctidae. The genus Subkossmatia is well known from Callovian ammonite faunas, with species characterised by robust, planispiral shells and distinctive ribbing. The species opis is particularly valued for its clear morphological features that distinguish it from closely related genera. These ammonites are important in stratigraphy, as they are associated with specific biozones used to date Jurassic deposits across the globe.

Morphology and Distinctive Traits

This specimen displays the diagnostic traits of Subkossmatia opis, including strong ribbing that radiates across the shell flanks and a tightly coiled, planispiral whorl structure. The ribs may bifurcate (split) towards the outer whorl, adding to the ornamental detail. The whorls are relatively compressed yet robust, providing both structural strength and hydrodynamic efficiency. Such ornamentation not only adds to the fossil’s beauty but also allows paleontologists to identify its evolutionary relationships and functional adaptations within the marine ecosystems of the Middle Jurassic.

Scientific and Stratigraphic Importance

Ammonites such as Subkossmatia opis are key index fossils, enabling geologists to date and correlate Middle Jurassic rock layers with precision. The species is part of the Callovian ammonite assemblages that help define important biozones across Madagascar and beyond. Fossils like this one provide crucial insights into the biodiversity of Jurassic seas and the evolutionary history of cephalopods. For collectors, it represents a fossil of both scientific importance and natural artistry.

Condition and Presentation

This fossil has been professionally prepared to retain its natural integrity while showcasing its intricate details. The ribbing, shell form, and whorl development are all clearly visible, making it a fine representation of the species. It is a one-of-a-kind specimen, not a replica or cast. The photographs provided show the exact fossil you will receive, ensuring complete confidence in its authenticity.

Guarantee of Authenticity

All of our fossils are 100% genuine, responsibly sourced, and scientifically identified. Each specimen is supplied with a Certificate of Authenticity. This Subkossmatia opis ammonite fossil from Madagascar is a rare and scientifically significant piece of Jurassic history, making it an exceptional addition for fossil collectors, natural history enthusiasts, and educational displays.