<p><strong>There is no strict definition of ammonites</strong></p>

<p>Ammonites are not strictly defined. One can reffer to ammonites as to the whole group of ammonoids (Ammonoidea, ammonites sensu latto). This is common, but not supported by most researchers. Researchers use the term "ammonoid" for paleozoic ammonoidea and "ammonite" for Jurassic and Cretaceous Ammonoidea (ammonites sensu stricto). Ammonites sensu stricto reffer to ammonoids with complex (ammonitic) sutures, which are typical for Jurassic and Cretaceous ages. However, complex ammonitic sutures are not exclusive for Jurassic and Cretaceous ammonoids. Ceratitic sutures are not exclusive for Triassic either and occur in Jurassic ammonoids, too.</p>

<blockquote>
  <p>So caution must be exercised when using suture lines as a means of classification. To obviate some of the problems posed by this
  simplistic classification, Wedekind, in 1918, introduced the terms
  palaeo-, meso- and neoammo-noids to classify ammonoids better.</p>
</blockquote>

<p>(PDF) Goniatites. Available from: <a href="https://www.researchgate.net/publication/262048294_Goniatites" rel="nofollow noreferrer">https://www.researchgate.net/publication/262048294_Goniatites</a> [accessed May 10 2019].</p>

CC BY-SA 4.0
2019-05-10T09:41:31.540Z
2019-05-10T21:48:31.687Z
2019-05-10T21:48:31.687Z
Petr Hykš
<p>I miss the definition of <strong>ammonite</strong>. In my opinion, many authors confuse the term "<strong>Ammonite</strong>" and "Ammonoid". Ammonoids (Ammonoidea) are large group of cephalopods including for example goniatites (Goniatitida), ceratites (Ceratitida) and <strong>ammonites</strong> (<strong>Ammonitida?</strong>). </p>

<p>EDIT: If you think that ammonites and ammonoids are the same, you are not right. Notice that researchers try to avoid using the term ammonite when talking about paleozoic ammonoids. Ammonites are usually refered to jurassic and cretaceous ammonoids. 
"While goniatites proliferated during the Carboniferous, ammonites thrived in Mesozoic times."
<a href="https://www.researchgate.net/publication/262048294_Goniatites" rel="nofollow noreferrer">https://www.researchgate.net/publication/262048294_Goniatites</a></p>

<p>But how can we strictly define "<em>true ammonite</em>"? Is it because of the ammonitic suture? This way, many triassic, jurassic, creataceous and possibly paleogenic (danian) ammonoids could be called true ammonites, because they have complex (ammonitic) sutures.</p>

<p>Can we call all jurassic and cretaceous ammonoids (phylloceratina, psiloceratina, lytoceratina, ammonitina, haploceratina, perisphinctina and ancyloceratina) <strong>ammonites</strong>? Can you show me where ammonites are on phylogenetic tree?</p>

CC BY-SA 4.0
2019-05-08T17:31:32.117Z
Perhaps better asked on the Biology site?
jamesqf
CC BY-SA 4.0
2019-05-08T19:58:50.183Z
Tags are for reference so those specialized in a particular field can find your question easily. not for including all related vocabulary.
John
CC BY-SA 4.0
2019-05-08T20:04:30.717Z
You may find this helpful. https://link.springer.com/chapter/10.1007/978-1-4757-9153-2_1
John
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2019-05-08T20:05:37.870Z
No that does not answer my question thanks.
Petr Hykš
CC BY-SA 4.0
2019-05-09T13:05:51.787Z
From everything I've found, ammonite and ammonoid are synonyms.
David Hammen
CC BY-SA 4.0
2019-05-09T22:18:46.110Z
All ammonites are ammonoids, but not all ammonoids are ammonites.
Petr Hykš
<fossils>
What exactly is ammonite?
Petr Hykš
# What exactly is ammonite?

(Asked by: username_0 on 2019-05-07)

I miss the definition of **ammonite**. In my opinion, many authors confuse the term "**Ammonite**" and "Ammonoid". Ammonoids (Ammonoidea) are large group of cephalopods including for example goniatites (Goniatitida), ceratites (Ceratitida) and **ammonites** (**Ammonitida?**).

EDIT: If you think that ammonites and ammonoids are the same, you are not right. Notice that researchers try to avoid using the term ammonite when talking about paleozoic ammonoids. Ammonites are usually refered to jurassic and cretaceous ammonoids.
"While goniatites proliferated during the Carboniferous, ammonites thrived in Mesozoic times."
<https://www.researchgate.net/publication/262048294_Goniatites>

But how can we strictly define "*true ammonite*"? Is it because of the ammonitic suture? This way, many triassic, jurassic, creataceous and possibly paleogenic (danian) ammonoids could be called true ammonites, because they have complex (ammonitic) sutures.

Can we call all jurassic and cretaceous ammonoids (phylloceratina, psiloceratina, lytoceratina, ammonitina, haploceratina, perisphinctina and ancyloceratina) **ammonites**? Can you show me where ammonites are on phylogenetic tree?

**Tags:** fossils

> **Comments:**
> **username_1**: Perhaps better asked on the Biology site?  
> **username_2**: Tags are for reference so those specialized in a particular field can find your question easily. not for including all related vocabulary.  
> **username_2**: You may find this helpful. https://link.springer.com/chapter/10.1007/978-1-4757-9153-2_1  
> **username_0**: No that does not answer my question thanks.  
> **username_3**: From everything I've found, ammonite and ammonoid are synonyms.  
> **username_0**: All ammonites are ammonoids, but not all ammonoids are ammonites.  

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## 1 answers

### Answer by username_0 on 2019-05-10. Score: 1 | Accepted answer

**There is no strict definition of ammonites**

Ammonites are not strictly defined. One can reffer to ammonites as to the whole group of ammonoids (Ammonoidea, ammonites sensu latto). This is common, but not supported by most researchers. Researchers use the term "ammonoid" for paleozoic ammonoidea and "ammonite" for Jurassic and Cretaceous Ammonoidea (ammonites sensu stricto). Ammonites sensu stricto reffer to ammonoids with complex (ammonitic) sutures, which are typical for Jurassic and Cretaceous ages. However, complex ammonitic sutures are not exclusive for Jurassic and Cretaceous ammonoids. Ceratitic sutures are not exclusive for Triassic either and occur in Jurassic ammonoids, too.

> So caution must be exercised when using suture lines as a means of classification. To obviate some of the problems posed by this
> simplistic classification, Wedekind, in 1918, introduced the terms
> palaeo-, meso- and neoammo-noids to classify ammonoids better.

(PDF) Goniatites. Available from: <https://www.researchgate.net/publication/262048294_Goniatites> [accessed May 10 2019].


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