ANCYCLOCERAS / ACRIOCERAS Heteromorph Ammonite – Hauterivian Cretaceous, Agadir Morocco

Description

Offered here is a rare and scientifically fascinating heteromorph ammonite fossil from the genera ANCYCLOCERAS and/or ACRIOCERAS, dating to the Hauterivian Stage of the Early Cretaceous Period. This well-preserved specimen was discovered in the Agadir region of Morocco, an area known for its fossiliferous marine strata and exceptional Cretaceous invertebrate diversity.

Taxonomic Classification:

• Order: Ammonitida
• Superfamily: Ancyloceratoidea
• Family: Ancyloceratidae / Acrioceratidae
• Genera: Ancycloceras / Acrioceras

Geological Context:

• Period: Cretaceous
• Stage: Hauterivian (~132–129 million years ago)
• Depositional Environment: Open marine setting with fine calcareous sedimentation. These ammonites lived in low-energy, outer-shelf environments where their unique coiling adapted them for slow movement or passive drifting in the water column.

Morphological Features:

• Classic heteromorph coiling with early open spiral whorls followed by elongated, hook-like or shaft-like extensions
• Prominent ribbing and occasional tuberculation, with irregular shell geometry that distinguishes them from planispiral ammonites
• These features are considered evolutionary responses to ecological pressures such as buoyancy control, mobility, and predator avoidance

Scientific Importance:

• Ancycloceras and Acrioceras are part of the diverse heteromorph ammonite clade, which showcases an evolutionary departure from traditional coiled forms
• These genera are useful in biostratigraphic correlation and palaeoecological reconstructions of the Tethyan marine realm during the Early Cretaceous

Locality Information:

• Agadir, Morocco – A renowned fossil locality yielding well-preserved specimens from Cretaceous marine formations, including ammonites, gastropods, and other invertebrates

Authenticity & Display:

All of our fossils are 100% Genuine Specimens and are accompanied by a Certificate of Authenticity. This listing includes photographs of the actual specimen you will receive. The scale rule cube = 1cm, with full dimensions shown in the photos.

This is a finely preserved example of Ancycloceras or Acrioceras, perfect for any collector of heteromorph ammonites, Cretaceous fossils, or marine palaeontology specimens.

Secure a fascinating piece of Earth’s evolutionary past—over 130 million years old and beautifully preserved from the ancient seas of Morocco.