Belemnites from Carniol France - Gargasian

[R0b]

Still more sorting to do but the belemnites are done. I am struggling to understand the differences between the different Neohiboletes. 
 

looking at http://le-coin-a-fossiles.fr/Gargasien.html there are three known species 

 

also from the topic below there are diplobelenid phragmacones

 

[R0b]

1 - 4

Are 1 and 2 the same? N. semicanaliculatus

Is 3 a misformed belemnite? 4 is for sure.

 

 

 

Edited October 24, 2021 by R0b
Image order

[R0b]

5-8

8 N. minimus?

 

 

 

 

Edited October 24, 2021 by R0b

[R0b]

And sorry to make @TqB drool diplobelenids are not very rare in Carniol

[TqB]

Yes, I'm drooling! And a nice wobbly pathology in one, as you say.

 

[R0b]

1 minute ago, TqB said:

Yes, I'm drooling! And a nice wobbly pathology in one, as you say.

 

Any idea on further identifications?

[TqB]

36 minutes ago, R0b said:

Any idea on further identifications?

Sorry, not without some literature. I've never looked at Aptian belemnites closely.

[R0b]

4 minutes ago, TqB said:

Sorry, not without some literature. I've never looked at Aptian belemnites closely.

Will have to do that myself than. Found a German blog that identifies the diplobelenids as Conoteuthis cf. dupiniana ORBIGNY, 1839.  But giving a forth species of Neohiboletes namely N. aptiensis. Shame I can’t find the book from Moosleitner and my French isn’t good enough.

[Ludwigia]

3 could be Duvalia dilatata.

[R0b]

48 minutes ago, Ludwigia said:

3 could be Duvalia dilatata.

Dilated that makes sense

 

thanks

[R0b]

@TqB

 

A general belemnite morphology question, how to determine the ventral or dorsal side?

 

The Neohibolites I found have three grooves, one short (ventral?) and two going the length (lateral?). The flattened one seems to have one groove going most of the length although covered in pyrite (ventral?) making it compressed.

 

Looked into Duvalia dilata but this species is much stronger compressed.

[TqB]

6 hours ago, R0b said:

@TqB

 

A general belemnite morphology question, how to determine the ventral or dorsal side?

 

The Neohibolites I found have three grooves, one short (ventral?) and two going the length (lateral?). The flattened one seems to have one groove going most of the length although covered in pyrite (ventral?) making it compressed.

 

Looked into Duvalia dilata but this species is much stronger compressed.

Ultimately, it's decided by structures other than the rostrum - most simply, the siphuncle is ventral so if there's a phragmocone you can section it to check. But very often the phragmocone is not preserved.

So technically you need an ID before you can tell if a single alveolar groove is ventral or dorsal.

In Neohibolites it is indeed ventral.

In Duvalia it is dorsal - your specimen does look a possible candidate for a relatively uncompressed Duvalia species although I believe the genus had disappeared by the Aptian. 

 

 

 

[R0b]

1 hour ago, TqB said:

Ultimately, it's decided by structures other than the rostrum - most simply, the siphuncle is ventral so if there's a phragmocone you can section it to check. But very often the phragmocone is not preserved.

So technically you need an ID before you can tell if a single alveolar groove is ventral or dorsal.

In Neohibolites it is indeed ventral.

In Duvalia it is dorsal - your specimen does look a possible candidate for a relatively uncompressed Duvalia species although I believe the genus had disappeared by the Aptian. 

 

 

 

Thanks the role of the siphuncle is what was missing.

 

Based on this graph in a publication I found they seem to indicate Duvalia has been found in Aptian formations.

 

 

[TqB]

2 hours ago, R0b said:

Thanks the role of the siphuncle is what was missing.

 

Based on this graph in a publication I found they seem to indicate Duvalia has been found in Aptian formations.

 

 

 

 

Fair enough! I only have a few papers on post-Jurassic belemnites.