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TqB
Thanks, Roger, I agree P. zieteni is the closest from the Upper Pliensbachian but I think this a separate species.

I have a few standard P. zieteni from the Upper
Pliensbachian/basal Toarcian, up to about the same size as
Schlegelmilch's but nothing yet approaches this specimen which is well
over twice the diameter of the largest.

It's very close to a specimen of P. robusta from the "Upper Lias" figured by Phillips (as B. latisulcata).
Of course this is quite a lot later (Falciferum and Bifrons Zones).

Tate & Blake tantalisingly mention something similar ("a stout bisulcate form of the digitalis group") as being "too rare to say more of it" in the Grey Shales (Tenuicostatum) which is getting closer...

The search is on for in situ specimens...

Tarquin
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Doggerfan
Then good luck on your search. A new species is always more than interesting, but like you say, you'll have to find it in situ.
Best wishes from the Lake of Constance. Roger.
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TqB
Thanks, Roger.

Next oddity - I posted this a while back but this is a new photo.

From Golden Cap, Green Ammonite Beds (alright, Seatown Marl MemberUnhappy ), lower Pliensbachian Maculatum Subzone.

Possibly a Coeloteuthis? - or something like a belemnotheutid (which aren't supposed to be around until the Callovian).

IMG_0669c_-_Copy.JPG 

IMG_0669c_-_Copy_2.JPG 

(The blotches are efflorescing salts - this has been sitting in a drawer for many years.)

Tarquin
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Doggerfan
I'd go for Coeloteuthis as far as size and stage is concerned. Hard to guess a species, though. C.palliata perhaps.
Best wishes from the Lake of Constance. Roger.
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TqB
Thanks, Roger! - good call, I think C. palliata (Dumortier) is a very good possibility.

 Dumortier's species was listed as "Middle Lias" so I'd skipped over it (I don't have the original, just the reference in Lissajous (1925)).
That must be an old usage though as I see Schlegelmilch puts Dumortier's specimen in "upper Lower Pliensbachian " which of course is spot on.

And it looks just like it too, complete with groove.

(To confuse the issue - following Tate & Blake (1875), the name is often given to a similar Upper Sinemurian form from Robin Hood's Bay - I'll post that next.)



Edited by TqB 2014-08-23 19:22:15
Tarquin
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Doggerfan
Lucky guess, I guess
Best wishes from the Lake of Constance. Roger.
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Doggerfan
I was just going through my old photos and discovered something interesting which I found a few years ago in the bifrons zone at the Lafarge quarry in Belmont, France. I'd forgotten all about it, although it's tucked away in one of the display cabinets. It shows what I believe to be an Acrocoelites type belemnite with the orthorostrum sticking out of the epirostrum. Please correct me if I'm wrong. It however does look similar to the A. inaequistriatus which is posted here near the bottom of the first page. It measures in at 9.5cm.

Be81a.jpg 
Be81b.1.jpg 

Edited by Doggerfan 2014-09-06 23:42:31
Best wishes from the Lake of Constance. Roger.
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TqB
Roger, what an excellent specimen! - I'm sure your diagnosis is spot on although I've never seen such a clear example.

A. inaequistriatus is a good possibility but the size also suggests A. longiconus (Schwegler, 1969).
To be honest, I can't tell them apart - the diagnoses and descriptions in Doyle's monograph have considerable overlap with the only real difference being that inaequistriatus is larger.

Thanks for showing it.
Tarquin
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Doggerfan
Hi Tarquin,

I don't quite understand. If A.inaequistriatus is longer then a length of 9.5cm would speak for that, wouldn't it?
Best wishes from the Lake of Constance. Roger.
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TqB
Maybe! - I forgot to add on a bit for your broken epirostrum...

The measured specimens (3) of A. longiconus specimens are 9.5-10cm without much epirostrum, thickness at alveolar apex 10-13mm.

A. inaequistriatus (5 specimens) are 11-16cm with variable epirostrum, thickness 15-25mm so perhaps more robust though some of mine are down to 13mm (16cm length).

A. longiconus perhaps develops an epirostrum at a shorter length of orthorostrum but I'd like to see some statistics and measured growth stages from sections to demonstrate a separation.

When you plot enough specimens, they tend to produce continua (like Howarth's Dactylioceras species).





Edited by TqB 2014-09-07 14:48:33
Tarquin
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Doggerfan
Thanks for the details. I think I'm leaning towards A.inaequistriatus now.
Best wishes from the Lake of Constance. Roger.
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TqB
Plenty more stuff waiting to go on here but here's a bonus one, sitting next to the mouth border of an Ibex Zone Lytoceras I collected yesterday - only spotted it when I got home.

Less than 4mm long, I think it's a juvenile Hastites.

IMG_0794c_-_Copy.JPG 

IMG_0798_-_Copy.JPG 


You can just see it below the middle of the mouth border (the ammonite is 20cm across and needs some prepping...):
IMG_0801_-_Copy.JPG 




Edited by TqB 2014-10-16 15:50:15
Tarquin
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TqB
Acrocoelites inaequistriatus - was pleased to find these at Sandsend last Wednesday in the Bituminous Shales, Howarth bed 42.

They were both detected in low angle sunlight as bumps in the shale, the belemnites being about a quarter of an inch underneath so they're not waterworn at all - the best specimens I have of this scarce species.

IMG_0842c_-_Copy.JPG 



Tarquin
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Doggerfan
Those look good! Congrats!
Best wishes from the Lake of Constance. Roger.
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TqB
Thanks, Roger! - just need a touch with an abrader to see the striations properly.
Tarquin
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valh
Hi Tarquin! Belemnites very nice! It was nice to see.
Valerij
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valh
Pachyteuthis mosquensis. Moskva,Filyovsky park. Upper Jurassic series,Tithonian,zona fulgens.IMG_00451.JPG 

Eulagonibelus volgensis. Mokva. Upper Jurassic,Tithonian,zona virgatus.

123.jpg 

Valerij
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TqB
Thanks, Valerij! - very nice to see Tithonian belemnites, there aren't any in the UK.
Tarquin
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valh
Thanks Tarquin! There is a lot of them directly in city.)
Valerij
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valh
Belemnite phragmocone.
Moscow region,Tithonian.
IMG_07181.JPG 
IMG_07211.JPG  


Valerij
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Doggerfan
Peekaboo! Now that's cute.
Best wishes from the Lake of Constance. Roger.
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Doggerfan
I recently found a couple of belemnites in the lower Kimmeridgian of the upper Danube Valley of which species I didn't yet have in the collection. The first one is a Hibolites semisulcatus measuring 7.5cm.

Be96.jpg 


The second is what I believe to be a Suebibelus pressuloides. Schlegelmilch puts it only in the uppermost Oxfordium, but I'm almost completely certain that it is one, particularly since it has the characteristic striae on both sides. I've nevertheless identified it with a "cf". These ones are apparently often regarded as the spawn of the above belemnite, so I'm showing part of the family album here

Be97a.jpg 
Be97b.jpg 




Edited by Doggerfan 2014-12-06 18:59:57
Best wishes from the Lake of Constance. Roger.
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TqB
Those are nice, Roger - how long is the pressuloides?
I have some tiny ones (below 1cm) from the Sengenthal Oxfordian which there's no reason to believe aren't juveniles of something (unlike pressulus which doesn't appear to get any bigger).
Tarquin
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Doggerfan
Sorry, I forgot to mention that it's 5cm. long.
Best wishes from the Lake of Constance. Roger.
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Doggerfan
I found another Hibolites semisulcatus the other day at the same site. This one is 10cm. long. Pity they always fall apart when you get them out, but at least they fit back together well.

Be98.jpg 



Best wishes from the Lake of Constance. Roger.
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TqB
Hi Roger - nice specimen of a beautiful species. I have a similar one from Grafenberg (big ones are hard to come by in the UK).

I'll post it and others soon - just changed my computer and haven't sorted out photos yet.
Tarquin
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Doggerfan
Hello again. I've just been advised by someone who knows to revise my tentative identification of Suebibelus cf. pressuloides to that of Hibolites semisulcatus. Apparently those striae on the sides are more common as imagined on hastate belemnites and probably have to do with fin attachments.
Best wishes from the Lake of Constance. Roger.
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TqB

A belated reply, Roger, and an excuse for some Speeton belemnites!

Here's an Aulacoteuthis ?descendens from the B beds (Barremian) showing nice lateral grooves.

IMG_0547c.jpg 


It also shows the alveolus extended by dissolution of the aragonitic part of the young rostrum - a clear change in angle between the true alveolus and the long, narrow pseudoalveolus.
IMG_0543c.jpg 



Edited by TqB 2015-01-16 13:04:58
Tarquin
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TqB
Closeup of the last one - having uploader problems again with no room for cursor...
IMG_0545c.jpg 
Tarquin
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TqB
This is a rare one (according to Swinnerton's monograph) - Hibolites obtusirostris, from Speeton, beds C5-6 (Hauterivian).

ventral view showing furrow:
IMG_0761c.jpg 



Edited by TqB 2015-01-16 13:05:42
Tarquin
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TqB
Large specimens of the common Hibolites jaculoides, bed C7: (I've shown some of these before, in a topic about the arrowed one which has tooth marks)
IMG_0516c.jpg 

Typical variation (including the above):
IMG_0515_-_Copy.JPG 

And one I managed to collect with the anterior part of the rostrum and phragmocone which are very fragile:
IMG_0506.jpg 
Tarquin
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Doggerfan
Very nice specimens!

Best wishes from the Lake of Constance. Roger.
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TqB
Thanks, Roger.


A few more Speeton ones:



Aulacoteuthis absolutiformis, base of B beds. At 125mm this is about as big they get. The alveolar section was in many pieces in the mud and I unfortunately missed a bit...

Dorsal:

IMG_1006c.jpg 



Ventral:

IMG_1007c.jpg 





A reasonable Acroteuthis subquadratus, D beds, ventral view:

IMG_0521c.jpg 



I've not yet been lucky enough to find one of the huge Acroteuthis lateralis but here's a bit of one that I bought, diameter a massive 4.2cm, shown next to the last one:

IMG_0522c.jpg 


 
Edited by Bill G 2015-01-26 10:04:10
Tarquin
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Austyn
with regard to Acrocoelites I must admit it is very difficult to subdivide. Doyle in his monograph is very confusing given that 3 apical grooves is supposedly indicative of Family, however in practice many ventral apical grooves are either weak or striated . Furthermore much subdivision is based on slightly different DV/L ratios or shape. This is clearly inadequate and needs further research.
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TqB
Austyn wrote:
with regard to Acrocoelites I must admit it is very difficult to subdivide. Doyle in his monograph is very confusing given that 3 apical grooves is supposedly indicative of Family, however in practice many ventral apical grooves are either weak or striated . Furthermore much subdivision is based on slightly different DV/L ratios or shape. This is clearly inadequate and needs further research.


Absolutely! - and welcome to the forum.

I once analysed about a thousand belemnites from the Lower Pliensbachian (mainly Belemnite Marls of Charmouth), using a lot of longitudinally sectioned specimens so that growth series could be plotted.
This seemed to be a practical way of delineating species - and threw up some possible instances of sexual dimorphism.

Edited by TqB 2015-01-25 17:58:39
Tarquin
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prep01
Don't keep us in suspense Tarquin - did you publish your findings?
Colin Huller
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TqB
Afraid not, Colin, I got my Ph.D with it and then drifted away from academia. I reckon the species are still viable but some of them would have to be renamed. 
Tarquin
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Austyn

Colin you beat me too it..I was just about to ask the same thing. It does sound very interesting..I remember a while back a case being put forward for sexual dimorphism in Youngibelus, though personally I wasn't convinced. Actually while on the subject I have noticed in a number of recent papers that Y. Tubularis and Y. trivialis  were renamed Cuspiteuthis. would appreciate any views any one has and if this has been universally adopted. Thanks
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TqB
Austyn wrote:

C
I have noticed in a number of recent papers that Y. Tubularis and Y. trivialis  were renamed Cuspiteuthis. would appreciate any views any one has and if this has been universally adopted. Thanks


Hi Austyn,

Thanks for pointing that out, can't believe I'd missed it but I've just checked some recent papers starting with Riegraf's (2000) on Schlotheim's type material.

Basically, yes, I gather this is the situation:

Cuspiteuthis Abel 1916 has been formally reinstated over Youngibelus Riegraf, 1980 by Riegraf himself.
He applies it particularly to Belemnites acuarius Schlotheim, 1820 and he includes B. tubularis Young & Bird 1822 in the genus having previously demonstrated that it was very similar and a probable close ancestor (there's only a subzone gap between them).

Pinard et al (2014) believe they may even be the same species.

trivialis is the non-epirostrid form of tubularis (Doyle called it simpsoni in his monograph but later corrected it to trivialis in his very useful 2003 paper on Simpson's type specimens) so of course is the same genus.

I'm not quite sure whether B. tubularis technically needs formal revision or whether Riegraf's earlier work counts (in 1984 with other authors) - I can't get hold of a copy and it's in German which I can't read.

He and other authors are using Cuspiteuthis in papers though and I'm very pleased to go along with it - it's the name I grew up with in older editions of the NHM Mesozoic Fossils handbook.

in 1984)

               
       
       
               

                       

                               

                                       

 


                               

                       

               
 






Edited by TqB 2015-01-26 17:53:31
Tarquin
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Hydrangea


Hi Tarquin - thanks for showing the Speeton belemnites.

I have a few collected from Speeton, also some Speeton erratics found on the Holderness coast .

This one was found loose on the beach at Speeton:-

belemnite_3_001.jpg 


belemnite_1_004.jpg 


Regards.


Roy D.
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TqB
Hi Roy,

Thanks, that's a super Acroteuthis lateralis, I'll just have to keep looking...

(It's nice to see a picture of one on the forum again - there were some on the old forum but the archive seems to have disappeared.)
Tarquin
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Hydrangea


Thanks Tarquin.

There was a huge fallen block on Speeton beach several years ago that was packed with thousands of Hibolites - all of them broken due to the nature of the clay.

I like to visit after heavy rain- it's a great place to collect trowels and chisels lost by previous collectors! Put them down covered in clay and you won't see them again!


These two belemnites are erratics:-

belemnite_6_001.jpg 

belemnite_7_001.jpg 


Regards.



Roy D.
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TqB
Very nice, Roy, both Speeton Clay Acroteuthis I think, look like A. subquadratus.
One of the few belemnites that can survive glacier transport more or less complete...
Tarquin
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Hydrangea


Thanks Tarquin.


Regards.

Roy D.
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Austyn
Hi Tarquin, thanks for the feedback. I think it is fair to say that Cuspiteuthis is now universally recognised. With regard to your earlier posts I think you are spot on with your observations that there is duplication within Cuspiteuthis. In the field the epirostrid forms can be seen to have epirostum complete to completely crushed. It is interesting to see in both Pinard et al and Doyle that Belemnites acuarius is defined as having a more conical orthorostrum  than Cuspiteuthis tubularis, though I suspect the only difference between them is based on the state of presevation of the epirostrum. Apparently B, acuarius is not seen in the UK yet I am sure that the type fossil was found in Yorkshire ! 
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