Barton Gastropods

[wessex_man]

As my first post was related to fragments of Volutospina [Athleta] gastropods found at the Barton formation Hampshire England. I thought I would post some examples from my collection showing the range size and species, which can be found on the formation.

The preservation of the shells is quite good the formation being mud based however aperture of the shell can get quite beat up which can be quite a pain when trying to identify species. Large examples being especially prone to some degree of damage.

The image of this shell was immortalized on the front cover of the British Caenozoic fossils (British National History Museum publication) as well as Illustrated guide to Barton Fossils Tony Saunders and John Cooper and the rear cover of Ray Chapmans Fossils of the Barton Beds. More recently Robert Plant has a conch on his recent album cover.

Volutospina luctator (Solander 1766) [Athleta lucator, Voluta luctatrix]. This can be found in size ranging juveniles up to full maturity the largest I have is about 120mm long. Most that I’ve found tend to be in the 25mm range.

Volutospina ambiguia (Solander 1766) [Voluta ambigua] is also frequently found.

[Herb]

nice specimens.!

[jkfoam]

Thank you for this post. I always enjoy seeing Barton fossils. Their high degree of preservation is always a pleasure to see.

The other thing I find very interesting is the faunal similarity between many of the Barton mollusca and the US Claiborne mollusca. The very upper Claiborne is close to the Barton stratigraphically and some of the molluscan fauna can be found in both locations, for example, the pteropod Skaptotion nitens (I. Lea). Many others look very similar but have different names. As an example is a picture of Athleta petrosus (Conrad) from the Cook Mountain formation, Claiborne from Brazos County, Texas

[Coco]

I suppose Barton is ... Bartonian ?

Coco

[MikeR]

Thank you for this post. I always enjoy seeing Barton fossils. Their high degree of preservation is always a pleasure to see.

The other thing I find very interesting is the faunal similarity between many of the Barton mollusca and the US Claiborne mollusca. The very upper Claiborne is close to the Barton stratigraphically and some of the molluscan fauna can be found in both locations, for example, the pteropod Skaptotion nitens (I. Lea). Many others look very similar but have different names. As an example is a picture of Athleta petrosus (Conrad) from the Cook Mountain formation, Claiborne from Brazos County, Texas

Jim--You beat me to posting about the similarities between the English Barton and the Southeastern U.S. Claiborne. Fossilworks lists the Upper Claiborne, which in my neck of the woods is Uppermost Lisbon, Gosport Sand, and the Moodys Branch Formation from the Jackson Group as Bartonian in age. Not only does Volutospina lucator bear a striking resemblence to Athleta petrosa, but Volutospina ambiguia is very similar to Athleta haleanus from the Upper Lisbon in Alabama.

Mike

P.S. I noticed that your photo was attacked by your spell checker. Athlete.

Edited February 8, 2015 by MikeR

[jkfoam]

Mike,

No, that was not a spell checker thing, it was one of my increasingly frequent senior moments! LOL

Jim

[wessex_man]

Thanks for your replies.

Hi Co-Co Yes Barton is Bartonian 38.0-41.3(Ma). In fact the Bartonian name is all down to th Swiss stratigrapher Karl Mayer-Eymar who just happened to be going around his business at Barton on Sea in the late 1850's and is used to define the period worldwide. see link http://en.wikipedia.org/wiki/Bartonian. We tend to drop the 'on sea' in the Uk as we do with a lot of coastal towns.

The US Claiborne sounds interesting are there any good sites with pictures I could have a look at?

We are lucky with the preservation of shell on most of the formation. Some of the species are found only in horizons where they are decalcified though.

Heres a few more

Volutospina athleta (Solander 1766) [Athleta athleta; Voluta athleta] example far right The other two are variety fortis

And a typical mixed bag after a collecting session my collecting box is approx 150mm. The larger finds I take en block mud wrap where necessary, bag up and excavate at home.

Some of the larger finds from this season.Generally its been poor with not much erosion.

[MikeR]

Here is a link which shows shells for the Stone City Beds/Cook Mountain Formation from the Brazos River in Texas. Click next to advance to the next page.http://www.fossilshells.nl/texeo01.html

[Coco]

Oh ! Very nice shells ! And long Dentalium !

Coco

[Clementine]

Hi everyone!

My dissertation in part has to do with Eocene Volute clades in England and the Gulf Coast. There have been some qualitative remarks published on the similarities of the faunas but I have yet to see an in-depth study on the topic. It's hard to compare the two without some consideration of the Eocene Paris Basin, which was a hotspot of marine biodiversity at the time. Interestingly, in their analysis on the evolution of Athleta petrosa stock in Texas, Fisher and Rhodda name Volutocorbis limopsis as the putative ancester of the clade containing Athleta tuomeyi, A. dalli, A. lisbonensis, A. petrosa petrosa and A. petrosa symmetrica. To me, it's a big stretch and probably not correct. Just superficially, they look nothing similar. I suspect the ancestor is from the other side of the Atlantic, among English/French faunas but I've only just begun an in depth look at this.

I was collecting some Barton material at Highcliffe just last week. I found some beautiful specimens which I'll post pictures of when I've cleaned them up. Also met a very nice gentlemen collecting along the beach who graciously donated a few of his volute specimens to me. So nice to meet you and it's lovely to meet new people who share my interests!

Figure from Rodda, P. & W. L. Fisher. 1964. Evolutionary features of Athleta (Eocene, Gastropoda) from the Gulf Coastal Plain. Evolution v. 18, n. 2, pp 235-244.

[PaleoWilliam]

Nice collection!

[Plantguy]

Yep, those are nice! I like the age/size progression photo.

Regards, Chris

[MikeR]

Hi everyone!

My dissertation in part has to do with Eocene Volute clades in England and the Gulf Coast. There have been some qualitative remarks published on the similarities of the faunas but I have yet to see an in-depth study on the topic. It's hard to compare the two without some consideration of the Eocene Paris Basin, which was a hotspot of marine biodiversity at the time. Interestingly, in their analysis on the evolution of Athleta petrosa stock in Texas, Fisher and Rhodda name Volutocorbis limopsis as the putative ancester of the clade containing Athleta tuomeyi, A. dalli, A. lisbonensis, A. petrosa petrosa and A. petrosa symmetrica. To me, it's a big stretch and probably not correct. Just superficially, they look nothing similar. I suspect the ancestor is from the other side of the Atlantic, among English/French faunas but I've only just begun an in depth look at this.

I was collecting some Barton material at Highcliffe just last week. I found some beautiful specimens which I'll post pictures of when I've cleaned them up. Also met a very nice gentlemen collecting along the beach who graciously donated a few of his volute specimens to me. So nice to meet you and it's lovely to meet new people who share my interests!

Figure from Rodda, P. & W. L. Fisher. 1964. Evolutionary features of Athleta (Eocene, Gastropoda) from the Gulf Coastal Plain. Evolution v. 18, n. 2, pp 235-244.

Hi Clementine

I have not read the Rodda & Fisher paper however they obviously considered Athleta evolution in the SE USA as a local event. If there were only one or two species involved one could claim convergent evolution, however there are so many different species with close similarities that I find it unlikely as well. One species, Conulina minax, is found in both in the French Lutetian and as a subspecies in the Ypresian of Alabama. Even early workers recognized a Tethyan influence in the American Paleogene fauna through at least to the early Miocene Chipola Formation in the Florida Panhandle. The Eocene version of the Tethys Ocean possibly had a east to west current flow prior to the Central America Isthmus formation which could have dispersed pelagic larva from Europe to North America.

As a geo/paleo/biology grad student at Cornell you are probably well aware of Warren Allmon's studies in speciation especially with gastropods. If you have not read it already, he addresses many of these questions on high level in

Allmon, Warren D. and Ursula E. Smith. 2011. What, if Anything, Can We Learn from the Fossil Record about Speciation in Marine Gastropods? Biological and Geological Considerations. American Malacological Bulletin, 29(1):247-276.

Mike

Edited February 12, 2015 by MikeR

[wessex_man]

Thanks Mike for the site link Its been very useful for comparing the species from different worldwide locations and I can see similarities. These type of sites show what the spirt of the internet is all about, information sharing. It took me ages to locate Burtons work on Barton and eventually found it via the Paleobiology data base, Encyclopedia of life http://eol.org/Not only does it aim to record current life on the planet but what has previously existed. Type in what you are interested in and you will see what I mean. It is obvoiusly an on going project but I've certainly seen it develop over the last five or so years.

We have been lucky in the UK in that Alan Morton http://www.dmap.co.uk/fossils/ has been working the Baton Beds via his website D-map and many local collectors have contributed to the site including myself. With Ian Wests Site http://www.southampton.ac.uk/~imw/index.htm they help immensley and may explain the rise general interest I have seen over the last ten or so years.

Thanks for you Comments Co- Co they are Dentalium bartonense a frequent find

Hi plantguy I've always tried where possible to collect an graduated range of a species to show their life cycle. It makes for a more interesting display. It is time consuming to do and can take years to get an example of a good mature adult.

Hi Clementine happy you were pleased with the specimens. it shows real dedication to travel long distances to persue your interests and you deserve success.

You talked about your interest in Volutospina nodosa. I didn't think I had found any but when looking back at my collection I have found that I was wrong

Identification can be a real challenge. The ones I've been looking to find out more about are below. The first is a bit like Volutospina lucator but it has a double row of spines, increased protection?

The other like Volutospina athleta but twists on the spines.

Anyone have any suggestions?

I don't know if you have heard of the Dent Collection but it is worth looking at for you studies. It is held and curated by the Bournemouth Natural Science Soc. http://www.bnss.org.uk/

Edited February 14, 2015 by wessex_man

[Clementine]

Dear Wessex_man,

In regards to your Volutospina luctator with 2 rows of spines, check out these specimens of Athleta tuomeyi. All were collected at Wood's Bluff, Alabama (Lower Eocene). The specimen on the right is similar in all regards except for the fact it has 2 rows of spines. How cool is that?

I've found only 1 reference to this variant (Toulmin, 1977) and I'm curious as to how common it is. Has anyone else found Athleta tuomeyi with 2 rows of spines? What about in any congeneric species?

[wessex_man]

Been just too busy and picked up your post.

This difference is not just limited to The Athleta genus. Here is a group from my collection of Cornulina minax (Solander) ranging in size from 40mm to 70mm in length. You will notice that in the second picture of two similar sized adults one has a second row of spikes. I think that this trait is likely to be found in other genera as well. I guess my question, by showing the original picture, is this a mutation in the species or are we talking new species? The same could be asked of your discovery interesting?

My usual Summer access and was lost to erosion a year back. So I haven't done as much collecting on the upper terraces this year. Its a bit too dry and crispy really waiting for the winter and wet!

must get around to posting some more of what I've got.

[wessex_man]

Thought I'd post a few Clavilithes

Clavilithes macrospira (Cossman) showing Juvenile to adult.

Normally you find them with the tips broken off but one glued back on with pva.

Clavilithes longaevus (Solander) The best of these come from a bed where the shell is soft and less well preserved.

Heres one with some ostrea sp. attachments

before removing last of clay

after

Edited October 8, 2015 by wessex_man

[Ludwigia]

I unfortunately can't contribute much to this thread, being a Jurassic man, but it's extremely interesting and educational! Welcome to the Forum, Wessex Man and please keep the posts coming

[DE&i]

On 2/14/2015 at 12:12 PM, wessex_man said:

Thanks Mike for the site link Its been very useful for comparing the species from different worldwide locations and I can see similarities. These type of sites show what the spirt of the internet is all about, information sharing. It took me ages to locate Burtons work on Barton and eventually found it via the Paleobiology data base, Encyclopedia of life http://eol.org/Not only does it aim to record current life on the planet but what has previously existed. Type in what you are interested in and you will see what I mean. It is obvoiusly an on going project but I've certainly seen it develop over the last five or so years.

We have been lucky in the UK in that Alan Morton http://www.dmap.co.uk/fossils/ has been working the Baton Beds via his website D-map and many local collectors have contributed to the site including myself. With Ian Wests Site http://www.southampton.ac.uk/~imw/index.htm they help immensley and may explain the rise general interest I have seen over the last ten or so years.

Thanks for you Comments Co- Co they are Dentalium bartonense a frequent find

Hi plantguy I've always tried where possible to collect an graduated range of a species to show their life cycle. It makes for a more interesting display. It is time consuming to do and can take years to get an example of a good mature adult.

Hi Clementine happy you were pleased with the specimens. it shows real dedication to travel long distances to persue your interests and you deserve success.

You talked about your interest in Volutospina nodosa. I didn't think I had found any but when looking back at my collection I have found that I was wrong

volut8.jpg volut9.jpg

Identification can be a real challenge. The ones I've been looking to find out more about are below. The first is a bit like Volutospina lucator but it has a double row of spines, increased protection?

volut10.jpg volut11.jpg

The other like Volutospina athleta but twists on the spines.

volut12.jpg volut13.jpg volut14.jpg

Anyone have any suggestions?

I don't know if you have heard of the Dent Collection but it is worth looking at for you studies. It is held and curated by the Bournemouth Natural Science Soc. http://www.bnss.org.uk/

Thank you for the dmap link as its proving to be very useful. As I've acquired quite a few Barton Bed gastropods such as this Athleta athleta.

[wessex_man]

Been a few years but I am still about. Ask people who collect The Barton formation what they wish to find and the answers is usually Hippochrenes amplus (Solander in Brander, 1766)

the Stromboidea Family of Gastrodods.

http://www.stromboidea.de/?n=Species.HippochrenesAmplus

http://eol.org/pages/4873104/details

Over the years I've been looking to that perfect example. it's a large target and very fragile.

The first example found was a memorable experience many people on the beach looking but I was lucky to observe a small part which was exposed.

 

 

for many years this was my best example

another

Back in 2012 I noticed some potential in the was rewarded in December with what I had been seeking for a good few years. Estatic was an understatement.

This shows you why it's so difficult to find a good example.

 

 

 

 

 

[FossilDAWG]

Wow, that is exquisite!   

Don

[Tidgy's Dad]

Absolutely stunning.

I have a reasonable Barton collection myself, but have never had so much as a sniff of a Hippochrenes! 

Excellent find. 

[ynot]

Very nice snails!

Thanks for sharing.

[wessex_man]

Thanks all for your kind comment's. Yes Tidgy' Dad The mature ones are very difficult. Would like to see what you have from Barton???

 

There were two of us on the Beach during a Storm Surge when that last one came, mad we are! Saw a hint of it, then partially exposed it. Suspected it was good protected it with mud and dug a block out for safe extraction in better surroundings. Thirty plus years of waiting just goes to show all comes to those who wait serendipity certainly smiled on me that day. I have seen many similar tales on the forum.

 

Now just trying to find one which is showing a transition from Juvenile to adult. I can't believe they put the wing on in such a short term.

 

A block for you all to look at

[ynot]

50 minutes ago, wessex_man said:

A block for you all to look at

That is quite busy isn't it.

What age is it?