Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun An extinct cephalopod mollusk of the order Ammonitida of the Permian to Cretaceous Periods, having a thick, usually coiled shell characterized by intricate suture patterns where the septa between individual chambers join the outer shell wall.
  • noun An ammonoid.

from The Century Dictionary.

  • noun One of the fossil shells of an extensive genus (Ammonites) of extinct cephalopodous mollusks (cuttle-fishes), of the family Ammonitidæ, coiled in a plane spiral, and chambered within like the shell of the existing nautilus, to which the ammonites were allied.
  • noun A name applied to certain explosive materials, patented by Favier, containing ammonium nitrate with other substances, chiefly nitro- or dinitro-naphthalene.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Paleon.) A fossil cephalopod shell related to the nautilus. There are many genera and species, and all are extinct, the typical forms having existed only in the Mesozoic age, when they were exceedingly numerous. They differ from the nautili in having the margins of the septa very much lobed or plaited, and the siphuncle dorsal. Also called serpent stone, snake stone, and cornu Ammonis.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun An explosive prepared from ammonium nitrate; amatol
  • noun Any of an extinct group of cephalopods of the subfamily Ammonoidea; a fossil shell of such an animal

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun one of the coiled chambered fossil shells of extinct mollusks

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[New Latin Ammōnītēs, from Latin (cornū) Ammōnis, (horn) of Amun, ammonite, genitive of Ammōn, Amun, from Greek : from Egyptian jmn.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

French ammonite, from Latin ammonis (cornua) "(horns of) Ammon".

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Examples

  • The closest living relative of the ammonite is the chambered nautilus.

    billingsgazette.com 2009

  • There are portraits and the wax seal, made from an ammonite, of the Very Reverend Dr. William Buckland, Dean of Westminster 1784-1856, a geologist who gave the first full description of a dinosaur, but who is better known for his stated ambition to eat a member of every living species of animal.

    Welcome to the Museum Of Weird and Wonderful Paul Levy 2011

  • At one key point in the book, a man picks up an ammonite, the shell of an ancient mollusk, and marvels at its weight in comparison with the dress pocket he has pulled it from; at another, a young mother stumbles upon a valuable painting hidden behind a dressing table.

    Advance reader reviews of The Hand That First Held Mine by Maggie O'Farrell. 2010

  • There are portraits and the wax seal, made from an ammonite, of the Very Reverend Dr. William Buckland, Dean of Westminster 1784-1856, a geologist who gave the first full description of a dinosaur, but who is better known for his stated ambition to eat a member of every living species of animal.

    Welcome to the Museum Of Weird and Wonderful Paul Levy 2011

  • She was still on a public footpath, for she had obediently followed signs, some marked with a white ammonite and some with the yellow traditional lettering carved into wood.

    Margaret Drabble | Trespassing 2011

  • One contained an ammonite, a fossilized nautilus shell.

    The Memory Palace Mira Bartók 2011

  • One contained an ammonite, a fossilized nautilus shell.

    The Memory Palace Mira Bartók 2011

  • Then he lifted its head, wheeled it about by the ammonite, spirograph shells of its horns till its eyes, on stalks, looked back at its bones.

    Archive 2009-02-01 Rus Bowden 2009

  • There's a point on the Corkscrew where for a split-second you can look ahead and to the side and get a cool view straight through the ammonite-spiral of the double loop.

    Round round get around I get around woooooo I get around Sci-Fi Gene 2009

  • There's a point on the Corkscrew where for a split-second you can look ahead and to the side and get a cool view straight through the ammonite-spiral of the double loop.

    Archive 2009-07-01 Sci-Fi Gene 2009

Comments

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  • Look! I found one of mollusque's ancient ancestors!

    August 29, 2008

  • I thought the Ammonites were a biblical tribe. :-)

    August 29, 2008

  • So did I. Apparently this particular biblical tribe featured coiled chambered shells.

    August 29, 2008

  • But which is more exciting ammonite or cummingtonite?

    March 4, 2009