Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: makszkaron on 05/10/2012 11:11:23

Title: Is this a fossilised crinoid in flint?
Post by: makszkaron on 05/10/2012 11:11:23

Hello everyone,

Recently I received a large flint nodule from Eastern Europe. After flaking off a piece of it I saw some kind of strange structure inside:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fimages35.fotosik.pl%2F1645%2F73f86f8da38e4d0fm.jpg&hash=3e3abbab92a033281587f73315166cce) (http://www.fotosik.pl/showFullSize.php?id=73f86f8da38e4d0f)

What do you think - is this some kind of fossil or rather a mineral inclusion?

And sorry for my English :/

Title: Re: Strange finding in flint
Post by: Mazurka on 05/10/2012 11:39:44

Nice find!

I would say that it is a fossil.

Flint forms as nodules on the seafloor - often around the remains of a creature and I would suggest that this is the remains of some sort of sponge as it does not look like a brachiopod or bivalve

Title: Re: Strange finding in flint
Post by: RD on 05/10/2012 13:20:33

 [ Invalid Attachment ]

It could be a mould of a fossil, e.g. like this mold of a crinoid (https://en.wikipedia.org/wiki/Crinoid) stem below ...

Quote

[ You are not allowed to view attachments ]
This  close up exemplifies the mode of preservation seen in most fossils found in the Redwall cherts, a hollow mold formed when the subject dissolves out leaving behind the exact form in reverse. Here we see a small 1/4 inch crinoid stem with its central canal seen as a pillar in the middle.

http://www.schursastrophotography.com/paleo/latest/youngredwall09.html

[ try a specialist forum ...http://www.thefossilforum.com/index.php/forum/14-fossil-id/  ]

Title: Re: Strange finding in flint
Post by: Mazurka on 05/10/2012 15:55:36

Crinoid stem looks like a good choice - better than a sponge (or bryozoan [;)])

Title: Re: Strange finding in flint
Post by: makszkaron on 05/10/2012 15:59:26

Here is a closeup at different angle:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fimages48.fotosik.pl%2F432%2F3ce940c11a51bdb1m.jpg&hash=95ed71e0d831a94fd1d14e13927ede77) (http://www.fotosik.pl/showFullSize.php?id=3ce940c11a51bdb1)

Quote from: Mazurka on 05/10/2012 15:55:36

Crinoid stem looks like a good choice

I agree.

Title: Re: Strange finding in flint
Post by: RD on 06/10/2012 10:30:13

Quote from: Mazurka on 05/10/2012 15:55:36

... (or bryozoan [;)])

In my defence there is nothing to indicate scale on the picture, (e.g. ruler, coin)

Title: Re: Strange finding in flint
Post by: makszkaron on 06/10/2012 11:46:14

Right.

The whole thing is about 3-4 cm (1.2-1.6 inch) in length.

Title: Re: Strange finding in flint
Post by: RD on 06/10/2012 12:50:40

I'm sticking with mould of a fossil : it looks like it's made of flint ...

  [ Invalid Attachment ]

A specialist fossil forum, e.g.  http://www.thefossilforum.com/index.php/forum/14-fossil-id/ , will be more likely to tell you what it's a mould of.

Title: Re: Strange finding in flint
Post by: bigblock on 11/10/2012 01:37:29

Looks like a harmonica :)  Whatever it is, it sure looks cool. Nice find.