Crioceras loryi

Ammonoidea, Oxynoticeratidae

Geological Time: Lower Cretaceous, Hauterivian Stage (~133 million years ago)

Size (25.4 mm = 1 inch): Ammonites are 46 mm and 40 mm across on a 163 mm by 95 mm base

Fossil Site: Vocantian Basin, Buis les Baronnes, Drome, France

Code: FA04

Price: $125.00 - sold

Description: A fine example of an ammonite of the genus Crioceras of the Hauterivian Stage (135 m.y.a) deposits of France. It has what is known as heteromorphic 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 herteromorph 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. As all ammonites, these went extinct at the end of the Cretaceous. This fine example shows a pair of these ammonites (note the spines on the larger specimen)..