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  • »Dawid Mazurek« ist der Autor dieses Themas

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Sonntag, 8. März 2015, 19:10

solved: NOT a hypostome ;)

The erratic is heavily weathered and in places covered with some Recent algae and lichens, so it's hard to tell the lithological type and thus age of the rock.
(edited)

Dieser Beitrag wurde bereits 1 mal editiert, zuletzt von »Dawid Mazurek« (8. März 2015, 19:50)


Jens

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Sonntag, 8. März 2015, 19:44

Hi Dawid,

mmh, where did you have collected, this looks for me not after a palaeozoic erratic. Its strongly reminds me after a the right valve of a Jurassic oyster, called Nanogyra nana. You should do some more cleaning and check the matrix. Its possible to find Oxfordian and Kimmeridgian erratics in Northern Poland;-) If its a grey marly limestone its possible of Kimmeridgian age. (There will be in a short time a nice paper about oysters written by me, so you can compare easily; or look for Pugaczewska, she did a nice work about Polish Jurassic oysters and figured lots of N. nana).

You should look at the broken region of the UFO, if you see any foliate structures there, then it will be without doubt an oyster;-) And for some reasons I do not see much similarities with a trilobite hypostom.

all the best,
Jens
Was wäre die Welt ohne Trilobiten.
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  • »Dawid Mazurek« ist der Autor dieses Themas

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Sonntag, 8. März 2015, 19:54

WOW, what a missidentification by me. It's the first time I found Jurassic oysters in an erratic boulder (or maybe it's just moved by human activity). I will try to clear or fragment the rock :) I am familiar with Nanogyra but was sure this must be something Palaeozoic.

Jens

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Sonntag, 8. März 2015, 20:13

Hi Dawid,

some Jurassic erratics are pretty rare, so no wonder that you were not familar with them. It could also be of Middle Jurassic age, if its contains enough silt. Anyway, I try to translate a german expression (infact its from the bible but I'm not familar with that book): "Anyone who is without sin may throw the first stone".

When you did not expect something then the fantasy let believe you things which can be explained in a better way;-) Anyway, I know a paper of a German amateur palaeontologist who interpreted a right valve of Nanogyra nana as an operculum of a gastropod. Hope it give you some comfort;-)

By the way, the erratic could be pretty rare where you found it and I would doubt that it was misplaced by another person there, it looks really after an erratic boulder.

all the best,
Jens
Was wäre die Welt ohne Trilobiten.
:267: :240: :272: