Is this a Juvenile Ammonite?

[Alvrr.0]

I want to buy this fossil if is a Juvenile 

[digit]

Could also be a simple gastropod. I'm not seeing any of the suture lines that would indicate ammonite but as we have no ammonites in Florida they are not my strong suit. Others with more authoritative replies will soon chime in.

 

 

Cheers.

 

-Ken

[fossils-uk]

This may not be a juvenile as many ammonites species are small to begin with. It would help if we knew the horizon it was found and the location found as we will be able to deduce the likely species it is and then be able to tell if it is a juvenile or not. 
please supply this data and I may be able to help 

[BobWill]

Keep in mind that being a juvenile has more to do with the number of whorls than the size.

[Alvrr.0]

14 hours ago, fossils-uk said:

This may not be a juvenile as many ammonites species are small to begin with. It would help if we knew the horizon it was found and the location found as we will be able to deduce the likely species it is and then be able to tell if it is a juvenile or not. 
please supply this data and I may be able to help 

Juvenile Apodoceras

200 Million years old

Lower Lias

Whitby

Thats the information they gave to me

[Alvrr.0]

10 hours ago, BobWill said:

Keep in mind that being a juvenile has more to do with the number of whorls than the size.

Maybe a subadult? 

[BobWill]

 If the Genus is correct then the number of whorls suggests it is an adult. Do you know the size?

[Alvrr.0]

1 minute ago, BobWill said:

 If the Genus is correct then the number of whorls suggests it is an adult. Do you know the size?

Juvenile Apodoceras

200 Million years old

Lower Lias

Whitby

They gave me that information 

[BobWill]

4 minutes ago, Alvrr.0 said:

Juvenile Apodoceras

200 Million years old

Lower Lias

Whitby

They gave me that information 

The small size indicates that it is a microconch, or male. The sexual dimorphism is extreme for this genus since the females are several times larger. All of the images I have seen for these have about the same number of whorls as this specimen and it's unlikely none of them would be adults.

[Alvrr.0]

8 minutes ago, BobWill said:

The small size indicates that it is a microconch, or male. The sexual dimorphism is extreme for this genus since the females are several times larger. All of the images I have seen for these have about the same number of whorls as this specimen and it's unlikely none of them would be adults.

So, in conclusion. Its a microconch from an Male adult Ammonite 

[fossils-uk]

I do not think it is an apoderoceras but in fact the inner whorls of something called polymorphites that is indeed a much smaller species from that area. 
if you look for a blog from Andys on the ammonites in that region you can see what I mean. Adult apoderoceras are much bigger. Again do an image search for apoderoceras and you see the difference. 

[Alvrr.0]

3 hours ago, fossils-uk said:

I do not think it is an apoderoceras but in fact the inner whorls of something called polymorphites that is indeed a much smaller species from that area. 
if you look for a blog from Andys on the ammonites in that region you can see what I mean. Adult apoderoceras are much bigger. Again do an image search for apoderoceras and you see the difference. 

Yes, I haven't notice that. So in conclusion. Its an adult Ammonite of a small size species? 

[BobWill]

5 hours ago, fossils-uk said:

I do not think it is an apoderoceras but in fact the inner whorls of something called polymorphites that is indeed a much smaller species from that area. 
if you look for a blog from Andys on the ammonites in that region you can see what I mean. Adult apoderoceras are much bigger. Again do an image search for apoderoceras and you see the difference. 

I don't know the genera found in that area well enough to judge and you may well be right, but when you say to look at the images I only found Apoderoceras macroconchs and they are many times larger than the microconchs. The ID given for the specimen may be from someone unaware of that, hence the incorrect designation as juvenile. The only images I found for Polymorphites also have ribs on the inner whorls and the same quadrate whorl section as the outer whorls, unlike the one here.