Notoceras Heteromorph Ammonite

Notoceras (Eubostrychoceras) indopacificum

Phylum Mollusca, Class Cephalopoda, Subclass Ammonoidea, Order Ammonitida, Suborder Ancyloceratina, Family Notoceratidae

Geological Time: Late Cretaceous, Coniacian Stage (~89 million years ago)

Size: 116 mm long by 70 mm wide, 30 mm across (uncoiled length 220 mm)

Fossil Site: Madagascar

Heteromorph AmmoniteDescription: This is an exceptionally fine heteromorphic ammonite that has been professionally prepared to display its beauty in 3-D. It has what is known as heteromorph shape. While most ammonites have spiral shells that retain the same shape throughout growth (homomorph), a major group of ammonites, the Ancyloceratina, emerged during the Late Jurassic which had uncoiled shells instead, and were called heteromorph ammonites (different-shaped). While little is known of their mode of life, their uncoiled shells would have precluded fast swimming. They may have wobbled their way through the water column with out-splayed tentacles, sweeping whatever came within their reach into their hungry mouths.

Also see: Other Ammonite Fossils

click ammonites pictures to enlarge

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