Crioceras loryi Ammonite
Phylum Mollusca, Class Cephalopoda, Subclass Ammonoidea, Order Ammonitida, Family Eoduroceratidae
Geological Time: Lower Cretaceous, Hauterivian Stage (~133 million years ago)
Size (25.4 mm = 1 inch): Ammonite fossil is 65 mm across on a 70 mm by 120 mm base
Fossil Site: Vocantian Basin, Buis les Baronnes, Drome, France
Fossil Code: FA06
Price: $125.00
 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. |
