Fossils from late ordovicium

[PaleoOrdo]

This weekend I visited again a late ordovicium site north of Oslo, as I now know is the katian period (that applies to the earlier posts on this website which I then, mistakenly, thought was middle ordovicium). First, for the first time I found two graptolites in a limestone, and first time in this site, I m not sure but I think it is graptolites, but it seems so.

 

Next, I found this stone which, I believe, includes an Gompoceras Nautiloid (the brown in the middle) and some nice gastropods. The size of the Nautiloid is about 4,5 cm.

 

And then this small gastropod presered in tre dimensions

 

 

[PaleoOrdo]

I also found, at the same site, this stone which I have no idea what is it. Anyone seen anything like it or have a suggestion?

 

 

 

[PaleoOrdo]

In a nearby site, which I think is early silurian I found this strange stone, anyone have an idea what is it? It must have been a very beautiful animal with colors originally!

 

 

Enlarged a part of the stone, but the part outside the wawe pattern.

 

[PaleoOrdo]

The sizes of the 2 last stones is about 10 cm for the first and 15cm for the last.

[PaleoOrdo]

I also found this nice coral. The length is 5 cm. It is a similar coral in the other part of the stone.

[minnbuckeye]

5 hours ago, PaleoOrdo said:

early silurian I found this strange stone, anyone have an idea what is it?

Stromatolite??

[PaleoOrdo]

Thank you for your reply. It made me read several articles about stromatolites and similar organisms today. After browsing though the information it seems to me that it is not a stromatolite, but a a sponge, namely a stromatoporoid, which we know is similar in appearance as stromatolites. I m not sure, but the structure seems to have a "wall-like" made up of bricks (seen in some parts of the picture) and root-like line structures, which is typical for these kinds of sponges. I may however be wrong and some expert on this site may correct me. Morover, I do nt know what the spheres in the stone may be.

Martin

[PaleoOrdo]

Maybe the sheres are cloths or rugose corals. Stromatoporoids have often corals together with them. Moreover, in early silur it is known that sponges was among the main survivors of the end-ordovician extinction event. That is maybe another indication that it is stromatoporoids?

[PaleoOrdo]

I also found this stone, in the first late ordovician site. But this seems to me to be a stromatolite.

 

The other side of the stone:

 

[Monica]

I love that little 3D gastropod that you found - it's adorable!

[PaleoOrdo]

I agree, Monica! It is quite impressive that its shape is preserved so many million years, just 1 cm long and it was just attached in 3D to the surface of a flat stone! The shell is of course spiral but that is not easy to see. I do not know the name of the species, but its shell is quite ovate-conic in shape with 5 whorls. 

Most gastropods I find is preserved in 2D, but there are some exceptions. Last week I found this beautiful speciemen at the same late ordovician site, also preserved in 3D. I should perhaps do some more prep to get out the whole form, but I am afraid to destroy it and the form is nicely seen as it is, more ornamented than other gastopods I have found. I think this species or shell-form is not often found, at least I never seen any like it. If someone know the family and species, I would like some help with ID or explanation of the shap of the shell.

And here seens from the other side

[PaleoOrdo]

The size of the gastropod in about 8 cm long.

[Tidgy's Dad]

I think stromatoporoids.

Love the gastropod. 

[PaleoOrdo]

Thank you. So, if you are right, I have found 2 stromatoporoids. Not easy for me to see the last one is stromatoporoid, but maybe you are right.

[PaleoOrdo]

I also found this stone at the same ordovician site. Is this also a stromatoporid? If so, how can one see it is not a stromatolite?