Description
- Sutured Flash Ammonite
- Species: Phylloceras sp.
- Age: Cretaceous, Approx 90–110 Million Years Old
- Source: Madagascar
- Size: Approx 40–90mm
- Exact item pictured
This specimen is a polished fossil ammonite from the genus Phylloceras, a group of marine cephalopods that lived in oceans worldwide during the Jurassic and Cretaceous periods. These animals were related to modern squid and octopus and possessed a coiled, chambered shell that helped regulate buoyancy.
Phylloceras is known for its smooth, rounded shell shape and complex internal suture patterns. The sutures are the lines formed where the internal walls met the outer shell, and in this genus they are highly folded and detailed, making them useful for identification and study.
These ammonites have been professionally polished to reveal natural iridescent “flash” caused by preserved layers of aragonite within the shell. Depending on the specimen and lighting, this flash may appear red, green, blue, or purple. The effect is similar to that seen in mother-of-pearl.
Madagascar is a major source of high-quality flash ammonites, with deposits that preserve both shell structure and colour exceptionally well. Specimens from this region are widely used in scientific collections and commercial fossil displays.
Each ammonite varies in colour, brightness, and pattern. This specimen shows the characteristic smooth form and sutured structure typical of Phylloceras and is suitable for display, study, or inclusion in a fossil collection.
