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whats the diffrence between goniatites and ammonites?


MRfossilMISTER

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when i look at goniatites and ammonites i see no diffrence. so what IS the diffrence between the two :headscratch: :blink:. :ammonite01:

 

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A good rule of thumb for differentiating between the two would be by checking the line pattern of the outside of the shell (known as suture lines). As shown in the diagram below, goniatites that show suture line almost always have a "wavy and sort of sharp" pattern. Many Ammonites (Family Ammonitida) on the other hand, have very complex suture lines that often appear to look like plant-shaped patterns.

 

Image result for goniatite vs ammonite

 

Image result for goniatite vs ammonite

Above is a picture of a goniatite and below is a picture of an ammonite. Notice the difference between suture lines (The ones on the ammonite are hard to see but can be found on the darker part of the shell at the left below the thumb)

Related image

 

However, this rule of thumb will not always work as both can be found with suture lines difficult to locate, if even preserved at all. While the setback is not too common in goniatites (unless it's raw and untreated), they constantly appear in ammonites. In this case, there are some other diagnostic features that show the fossil in question is more likely to be an ammonite. As far as I know, iridescence, a feature that is commonly found in some fossil ammonites is seldom found in goniatites, if found at all. Another feature would be a clear and significant three-dimensional texture of the shell, which goniatites lack but many species of ammonites posses, especially Jurassic species.

 

CORRECTION: The suture lines actually specifically exist inside the exterior shell, meaning that if the shell is fully preserved, suture lines will not show as they are obstructed by the outermost layer.

If you're a fossil nut from Palos Verdes, San Pedro, Redondo Beach, or Torrance, feel free to shoot me a PM!

 

 

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Ammonites and Goniatites are both Ammonoids, but indeed the goniatite suture lines are a lot less complex than the suture lines of the ammonites.

 

They both have a ventral siphuncle, this is specific for al the ammonoids ( this includes: Bactrites, Goniatites, Ceratites, Ammonites )

 

Also Goniatites ar only found in the Paleozoic, and Ammonites only in the Mesozoic.

 

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