Iridescent Desmoceras Ammonites

Name: Desmoceras latidorsatum

Phylum Mollusca; Class Cephalopoda; Subclass Ammonoidea; Order Ammonitida

Geological Time: Middle Cretaceous, Albian Stage (150 mya)

Size (25.4 mm = 1 inch): 47 mm and 43 mm diameter Matrix: 72 mm by 43 mm

Location: Mahajanga, Madagascar

Description: This fine ammonite pair is called Desmoceras latidorsatum from Madagascar which has much of the original iridescent shell present. This iridescence is a consequence of light passing through the various layers of aragonite and conchiolin deposited by the ammonite in life. The lack of acidity in the depositional environment allowed them to be preserved as you see it here. Notice the play of colors when the viewer’s aspect changes.

click ammonite pictures to enlarge

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