Fossil from the lower Jurasic, Holzmaden, Germany

[DrDu]

Recently, I collected fossils from the famous posidonia shells from the lower Jurasic (Toarcium or Lias epsilon) in Holzmaden in the south west of Germany near Stuttgart. Besides numerous Ammonites I found some of the following fossils which I don't quite know what it is. Any ideas?
They are quite thick "leaves" which seem to be connected to some thicker more or less spherical stem(now completely pyritized in the upper part of the picture) altough I did not prepare them, so the anatomy is just a guess. The size is about 3 cm.

Thank you!

 

[Evo]

They remind me of ginko, but I'm not sure if they lived where you found this, but they do date back to the lower Jurasic.

 

[davenn]

looks like the typical brachiopod of that era
I have collected a good few out of the Jurassic strata on the SE coast of the South Island of New Zealand, part of the Southland Syncline

cheers
Dave

 

[DrDu]

Thank you for your replies!
I don't think it is gingko, although gingko leaves have been found at that site, because it is a marine environment and leaves of land plants are rare.
I was considering also brachiopods, but they are a little bit too irregular and this does also not explain the stem.
Now that I was looking for brachiopods, I found some pictures of crinoids from Holzmaden which seem to be quite similar:
http://www.erftalnews.de/Bilder/Sammlung/Seelilien/Holzmaden_Seelilie_2.jpg

 

[davenn]

that link won't open, can you post a pic here please

not sure what the "stem" is that you are seeing ?

of course there's no reason why you wouldn't have a crinoid and a brachiopod in close proximity

I would be VERY suprised if that main object in the centre isn't a brachiopod

they come in all sorts of variations and ones from that far back in time are often have quite distorted shapes due to the pressures of burial

cheers
Dave

 

[DrDu]

that link won't open, can you post a pic here please

Strange, maybe you can surf to
http://www.erftalnews.de
Then click on "Sammlung"->"Seelilien"

 

[Evo]

I have tons of crinoid fossils, they're everywhere here, in my yard. Is the picture you posted a disc from the stem? I've never seen a crinoid with "leaves" like that. They're actually not a plant.

https://www.google.com/search?q=cri...W36IDADQ&sqi=2&ved=0CJYBEIke&biw=1010&bih=598

I did find this photo of a brachiopod that does look similar to your picture, not like the distinct brachiopods I find here. Letter T is the brachiopod.

http://en.wikipedia.org/wiki/File:ThecideanZalas.jpg

 

[edwardr]

It looks to me like a type of foraminiferan known as a nummulite. I've found plenty of these myself in Miocene limestone. I don't think they've been found in Cretaceous rock though.

http://en.wikipedia.org/wiki/Nummulite

 

[DrDu]

According to the german wikipedia, nummulites are first found in the upper Cretaceous rocks. But my fossils are definitively from the lower Jurassic.

 

[Evo]

It really doesn't look exactly like anything I've seen, but it's difficult from only a picture, but you seem to know your fossils and you're stumped. If you have a local university, perhaps someone in the paleontology department could identify it.

 

[DrDu]

According to the german wikipedia, nummulites are first found in the upper Cretaceous rocks. But my fossils are definitively from the lower Jurassic.

 

[DrDu]

The problem is that I haven't got any books on fossils, but it seems I have to change this.
Holzmaden is one of the most famous sites in Germany for fossils and I am quite sure that this relic, which seems to be relatively abundant, is described somewhere.

 

[edwardr]

You might want to run it by this community:

http://www.thefossilforum.com/index.php?/forum/14-fossil-id/

 

[DrDu]

I think I got it: It isn't a fossil at all but a pyrite sun, i.e. a pyrite formation of inorganic origin.
See e.g.
http://www.holzmadenfossilien.de/inhalte%20fossilien/Pyritsonne%20003.html

 

[Evo]

I think I got it: It isn't a fossil at all but a pyrite sun, i.e. a pyrite formation of inorganic origin.
See e.g.
http://www.holzmadenfossilien.de/inhalte%20fossilien/Pyritsonne%20003.html

Wow, it does look like a fossilized plant.

 

[DrDu]

As a reward for your help I upload here a picture of a real fossil found there. I exaggerated the contrast somewhat, but this more how it looked when it was fresh and wet.

 

[Evo]

As a reward for your help I upload here a picture of a real fossil found there. I exaggerated the contrast somewhat, but this more how it looked when it was fresh and wet.

Very nice!