Is this a banded flint pseudo fossil or a soft bodied worm?

[Graham Hill]

Hi, I split flint pebbles on a beach at Wherrytown, Cornwall, UK to use as chisels to carve granite and dolerite sculptures. This one cleaved nicely and on each facet had near identical patterns. I have seen thousands of flint facets and expect a few fossils, however this looks like a soft bodied creature; Annelida hirudinea. It looks segmented and has iron compounds within as though remains of blood. Have I been fooled by banded flint or is this remarkable preservation of something like a fish leach?

Graham

[westcoast]

On initial viewing, i think your instincts are right, that does look remarkable! Others with more local knowledge will chime in shortly.

[TqB]

That's a weird one. It doesn't strike me immediately as banded flint and flint does sometimes host unusual preservation (e.g. of plants). I don't know what it is (I'd love it to be a worm but it's unlikely!) and I think it's worth contacting, say, the Natural History Museum. 

[Tidgy's Dad]

Certainly worth checking out.

Very interesting. 

[Graham Hill]

Thanks,

I have recently sent the image to Natural History Museum and if they want to see it I will take it to them. Any ideas what it could be if not banded flint?

[Tetradium]

4 hours ago, Graham Hill said:

Hi, I split flint pebbles on a beach at Wherrytown, Cornwall, UK to use as chisels to carve granite and dolerite sculptures. This one cleaved nicely and on each facet had near identical patterns. I have seen thousands of flint facets and expect a few fossils, however this looks like a soft bodied creature; Annelida hirudinea. It looks segmented and has iron compounds within as though remains of blood. Have I been fooled by banded flint or is this remarkable preservation of something like a fish leach?

Graham

This is a perfect example of why flint cant always be dismissed as not having fossils. Flint is such a bizarre and unpredictable mineral. 

[JohnJ]

26 minutes ago, Tetradium said:

This is a perfect example of why flint cant always be dismissed as not having fossils. Flint is such a bizarre and unpredictable mineral. 

 

I don't remember anyone dismissing flint as void of fossils.  It is actually well known to be a common source of specimens.

 

It will be great if the museum gets a chance to review it.

[abyssunder]

Crinoids may look like this if a segment of the column is infested by epibionts.

 

Edited July 1, 2021 by abyssunder

[Graham Hill]

I need to do some research on this! Have you a source I can open access abyssunder? 

[Graham Hill]

Hi abyssunder,

First paper free online I found is 'Epibionts on upper Eifelian crinoid columnals from the Holy Cross Mountains, Poland EDWARD GŁUCHOWSKI'. Scale of segmentation could fit at about 0.5mm and I will read this and other work carefully. With respect you may be on to something with identification.

[DPS Ammonite]

To differentiate between a crinoid stem column and a creature such as a leech look to see if there is 3 D preservation. A crinoid stem whether carbonate or silicified should stick out in 3 D from the matrix. The boundaries between disks should be zigzag. A leech should be preserved in a plane commonly as a carbonaceous or iron rich film. It sort of looks like the preservation is in a plane as a film. Is that what you see?

 

To determine if the rock is chert, scratch it with a steel object (pin or knife) on a part away from the possible fossil. Steel will not scratch chert.

[TqB]

Many weird things in UK flint (which is always from the Cretaceous Chalk) end up being identified as sponge fragments of which there is a huge variety. This is possibly a section through a bit of wall, but I'm by no means sure.

Edited July 1, 2021 by TqB

[DPS Ammonite]

If Cretaceous, crinoid stems are unlikely.

[Graham Hill]

Was running with crinoids. Am I right that this flint pebble is most likely Upper chalk, late  Cretaceous so Crinoid stems are not a fit? 

[abyssunder]

32 minutes ago, Graham Hill said:

Hi abyssunder,

First paper free online I found is 'Epibionts on upper Eifelian crinoid columnals from the Holy Cross Mountains, Poland EDWARD GŁUCHOWSKI'. Scale of segmentation could fit at about 0.5mm and I will read this and other work carefully. With respect you may be on to something with identification.

That's a very good paper I'm referring to.

17 minutes ago, DPS Ammonite said:

If Cretaceous, crinoid stems are unlikely.

Why?

[DPS Ammonite]

8 minutes ago, abyssunder said:

25 minutes ago, DPS Ammonite said:

If Cretaceous, crinoid stems are unlikely.

Why?

Crinoids with stems became really rare after the Permian. I have never collected a crinoid stem from Cretaceous or newer rocks. Paleozoic crinoid stem fossils are abundant.

Edited July 1, 2021 by DPS Ammonite

[Graham Hill]

Lots to catch up with. This blog is faster than me. Yes I worked out crinoids unlikely if Cretaceous. To DPS Ammonite, it all looks flat though you should see it yourself. There is nothing hard standing out spared when splitting. TqB I would like to see into the stone either side of the split to see if the pattern extends like a sponge- not a worm. Do not have the technical means. All I can say is that there are no patterns running in the cortex that might indicate that.

[Graham Hill]

Oh here is a mea culpa (to be posh). I wanted to flake away a thin partly separated flake just past the bulbous end of the 'worm' to see if it terminated underneath with a sucker like a leech. The opaque thin flint of sub 0.1mm thickness did fracture using a steel pin with no definite results. I did leave some artefacts of steel embedded on the flint/chert. Schoolboy error! I do know the Mohs scale.

[abyssunder]

24 minutes ago, DPS Ammonite said:

Crinoids with stems became really rare after the Permian. I have never collected a crinoid stem from Cretaceous or newer rocks. Paleozoic crinoid stem fossils are abundant.

I agree with you, but there will be exceptions.

https://www.bgs.ac.uk/discovering-geology/fossils-and-geological-time/crinoids/

18 minutes ago, Graham Hill said:

Oh here is a mea culpa (to be posh). I wanted to flake away a thin partly separated flake just past the bulbous end of the 'worm' to see if it terminated underneath with a sucker like a leech. The opaque thin flint of sub 0.1mm thickness did fracture using a steel pin with no definite results. I did leave some artefacts of steel embedded on the flint/chert. Schoolboy error! I do know the Mohs scale.

More pictures from different angles may help us. 

[Graham Hill]

Thanks abyssunder. At the moment I am working with a 5MP digital microscope to USB computer port with 300X  magnification digital, whatever that means (I will give you a scale bar). The specimen is 'flat' though not enough for the depth of field for microscopy so montages always have focus decisions made for best fit. I will be buying an old school compact camera (remember them) tomorrow. My feeling is that at higher magnification it blurs out. There is not greater detail much beyond what you have seen, but I will answer all questions with photos you ask for. If it is worthy then other means such as XRD might help. Not there yet. Ask for pictures. I will do my best.

[Graham Hill]

Still looking at crinoids, present until now, lots to learn.

[abyssunder]

25 minutes ago, Graham Hill said:

Thanks abyssunder. At the moment I am working with a 5MP digital microscope to USB computer port with 300X  magnification digital, whatever that means (I will give you a scale bar). The specimen is 'flat' though not enough for the depth of field for microscopy so montages always have focus decisions made for best fit. I will be buying an old school compact camera (remember them) tomorrow. My feeling is that at higher magnification it blurs out. There is not greater detail much beyond what you have seen, but I will answer all questions with photos you ask for. If it is worthy then other means such as XRD might help. Not there yet. Ask for pictures. I will do my best.

Thank you!

Do you see something along the segmented specimen what looks like spines or crinoid cirri scars?

[DPS Ammonite]

See pictures of Cretaceous worms from fossil museum.net:

http://www.fossilmuseum.net/Fossil_Sites/Lebanese-Lagerstatt/Annelida/Annelid-fossils.htm

 

 

Edited July 1, 2021 by DPS Ammonite

[Kosmoceras]

5 hours ago, Graham Hill said:

Thanks,

I have recently sent the image to Natural History Museum and if they want to see it I will take it to them. Any ideas what it could be if not banded flint?

 

I'm not sure what it is either, but it looks unusual. I'm not aware of any Cretaceous deposits in the area around Wherrytown - is there any of this chert in situ? If I remember I'll ask some of my colleagues at the NHM tomorrow and see if anyone has any ideas. 

[TqB]

8 hours ago, Kosmoceras said:

 

I'm not sure what it is either, but it looks unusual. I'm not aware of any Cretaceous deposits in the area around Wherrytown - is there any of this chert in situ? If I remember I'll ask some of my colleagues at the NHM tomorrow and see if anyone has any ideas. 

I think the flint is from from pebble deposits in the Channel. The nearest Chalk outcrops are indeed a long distance away on the eastern Devon coast. 

Edited July 2, 2021 by TqB