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Microconch And Macroconch?


Rafel_93

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Hello!

I just wanted to ask what are 'microronch' and 'macroconch' in ammonites, just because I've noticed that these words are used in lots of articles but they're never explained (guess it's quite 'basic', but I just don't know and can't find what are them).

Thank you in advanced! ;)

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I believe the microconch is a male specimen,(smaller), of an ammonite species, while the macroconch is the female, (larger).

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KOF, Bill.

Welcome to the forum, all new members

www.ukfossils check it out.

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Definition for macroconch:

Web definitions: Referring to the female form of an ammonite, in which the female of the species had a larger shell than the male, or microconch..

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  • 8 years later...

Because of sexual dimorphism, a macroconch may be up to 400% larger than the microconchs.

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The microconches (males) often have lappets at the mouth aperture. Here is an example of a Normannites sp. (4.5cm. diameter)

A826d.1.thumb.jpg.7ee1af804204d06cb1f93e80c9869eb6.jpg

 

This is the microconch to the Stephanoceras sp. macroconch (female), an example of which is pictured below. This one has a real diameter of 14.5cm., but an apparent complete diameter of ca. 18-20cm., since the last part of the outer whorls is missing.

A824a.1.thumb.jpg.8d8c113687cd107efec914ae5300f89b.jpg

 

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Greetings from the Lake of Constance. Roger

http://www.steinkern.de/

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  • 8 months later...

Hi,

So how can you tell the difference between a young female and a grown male ammonite if they are the same size? Are there any differences in the whorls for example? Is the female body chamber slightly bigger/wider?

Cheers in advance!

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7 hours ago, mcfossils said:

Hi,

So how can you tell the difference between a young female and a grown male ammonite if they are the same size? Are there any differences in the whorls for example? Is the female body chamber slightly bigger/wider?

Cheers in advance!

 

One can sometimes not tell the difference, especially if the male has no lappets and is not complete, since the diagnostic features on the inner whorls are similar. Only when the female has grown older do the features begin to diverge. However, if the small ammonite is obviously complete with living chamber, then it must be a male, since in the female, the phragmocone alone is always larger than a complete microconch.

 

Greetings from the Lake of Constance. Roger

http://www.steinkern.de/

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2 hours ago, RJB said:

My problem is that for the life of me, I can never remember which is which. 

 

RB

The female has to have space for eggs, so it is bigger (macroconch). 

 

Don

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21 hours ago, FossilDAWG said:

The female has to have space for eggs, so it is bigger (macroconch). 

I understand that.  I simply can never remember which is which. 

 

RB

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