RARE 5.25″ Dichotomosphinctes anticedens Fossil Ammonite | Callovian Jurassic | TULEAR Madagascar | Genuine with CO

Description

RARE: Dichotomosphinctes anticedens Fossil Ammonite (5.25″)

Geological Age: Callovian, Middle Jurassic (~166 to 163.5 million years ago)

Location Found: Tulear (Toliara), Southwestern Madagascar

Fossil Type: Ammonite (Extinct Marine Cephalopod)

Species: Dichotomosphinctes anticedens

Order: Ammonitida

Superfamily: Perisphinctoidea

Family: Perisphinctidae

Specimen Overview:

This 5.25-inch fossil ammonite is Dichotomosphinctes anticedens, a rare and finely detailed species from the Callovian stage of the Middle Jurassic. Sourced from the renowned fossil beds near Tulear in Madagascar, this specimen offers both collector-grade preservation and fascinating palaeontological value.

The photo shows the actual fossil specimen for sale. A 1cm scale cube is provided for size reference. Please review the image for accurate dimensions and condition.

Geological Context & Depositional Environment:

During the Callovian, Madagascar was covered by warm, shallow seas ideal for marine biodiversity. The region around Tulear formed part of a vast epicontinental sea on the southern margins of Gondwana, where calcareous muds and marls accumulated—preserving marine invertebrates in exquisite detail.

These fossil-rich layers are often associated with classic ammonite-bearing zones, including the Macrocephalites and Reineckeia zones, important for Jurassic biostratigraphy.

Morphology & Notable Features:

Dichotomosphinctes anticedens is recognised by its evolute coiling, deep umbilicus, and sharply bifurcating ribs. These ribs start from prominent nodes at the umbilical shoulder and branch into two or more strong ribs that sweep across the flanks and venter.

This 5.25″ specimen shows excellent preservation of these distinctive ribbing features and symmetrical shell structure. Its well-defined ornamentation and fine detail make it an excellent reference example of mid-Jurassic ammonite morphology.

Authenticity & Guarantee:

All of our fossils are 100% genuine specimens and come with a Certificate of Authenticity. Each piece is carefully selected, professionally prepared, and stabilised to ensure long-term preservation and quality display.

Perfect For:

• Fossil and ammonite collectors
• Academic study and educational display
• Natural history museum collections
• Home décor or unique scientific gifts

Bring home an authentic piece of Jurassic marine life with this rare Dichotomosphinctes anticedens ammonite—expertly preserved from the famous fossil beds of Tulear, Madagascar.