Printer Friendly
Dictionary, Encyclopedia and Thesaurus - The Free Dictionary
1,519,180,962 visitors served.
?
Dictionary/
thesaurus
Medical
dictionary
Legal
dictionary
Financial
dictionary
Acronyms
 
Idioms
Encyclopedia
Wikipedia
encyclopedia
?

ammonoid

   Also found in: Dictionary/thesaurus, Wikipedia, Hutchinson 0.03 sec.

ammonoid

Enlarge picture
Polished cross section of a Middle Jurassic ammonite from southern France; in the Eichstätt …
(credit: Lilly Stunzi-Zurich-New York)
Any of a group of extinct shelled cephalopods, related to the modern pearly nautilus, that are commonly found as fossils in marine rocks of the Devonian through Cretaceous periods (410–65 million years ago). Most ammonoids were predators. The shells, either straight or coiled, served as protective and supportive structures and enabled the animals to compensate for varying water depths. Ammonoids are important index fossils because of their wide geographic distribution in shallow marine waters, rapid evolution, and easily recognizable features. See also belemnoid.
?Page tools
Printer friendly
Cite / link
 Email
Feedback
? Mentioned in
No references found
 
Encyclopedia browser? ? Full browser
 
 
Encyclopedia
?

Disclaimer | Privacy policy | Feedback | Copyright © 2009 Farlex, Inc.
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional. Terms of Use.