Tooth in Posidonia Shale, Holzmaden/Ohmden (Southern Germany)

[Laleja]

Hello to all,

 

this is a tooth I happened to find in Posidonia Shale in Ohmden (near Holzmaden) in Southern Germany. It's a bit less than 1 cm.

I would love to know to whom it belonged originally - is it possible to identify it? I know that Ichthyosaurus and Steneosaurus may be found there, could it be one of the two?

 

I would be glad if someone could tell.

 

Thank you already,

Laleja

[Kikokuryu]

Don't quote me on this, but the irregular striations you see here is what you'd expect to see in marine crocs (thalattosuchians) like Steneosaurus.

 

It's unlikely to be ichthyosaur as their striations go straight down. Sauropterygians like plesiosaurs (+Pliosaurs) I think tend to be something in between, and can be mistaken for either.

 

While it's not visible here and likely hidden under the matrix, crocs also have a carinae, while the ichthy/plesios usually don't with maybe a few exceptions.

 

So it's likely a teleosauroid crocodylomorph like Steneosaurus.

[North]

Steneosaurus would be my first thought too. But Im not very familiar with the location. So Im not totally confident, expecially without seeing the whole tooth.

[Laleja]

Thank you so much! As Steneosaurus bollensis is typically found in the area, I guess it might perhaps be one. I'm glad to have learned about the different striations. I've looked at some tooth photos and begin to see the difference.

[rocket]

nice find, go to prep it, should be Steneosaurus.
Rare find, they do not come up very often, sometimes, but not very often

[Laleja]

10 hours ago, rocket said:

go to prep it

That's something I have never done. I will leave it in the matrix, it will be better like this: I don't want to damage it.

I'm so happy that I found it... It was my first visit to Holzmaden and Ohmden (or any other fossil quarry) since I was a child and I wished to find a Steneosaurus tooth.

 

I will address it as Steneosaurus as long as it doesn't veto.

[pachy-pleuro-whatnot-odon]

As others have said, this is a teleosaurid crocodile tooth. Most ichthyosaur teeth from Holzmaden/Ohmden - whether Stenopterygius sp., Temnodontosaurus trigonodon, or Eurhinosaurus longirostris - don't bear any ornamentation, with those found elsewhere exhibiting the traditional plicidentine enamel folds. Plesiosaur and pterosaur remains from the area are extremely rare, with me actually never having seen a confidently identified plesiosaur tooth. And also, the latter would have a different type of striation.

 

So, yeah, Macrospondylus 'Steneosaurus' bollensis seems the appropriate ID, with its carinae likely lying in wait underneath the overlying shale. You could carefully try removing this shale using a sharp and, preferably, flexible needle, carefully prying away at it, until more of the tooth is exposed. @belemniten

[Laleja]

Great!! Thanks a lot.

37 minutes ago, pachy-pleuro-whatnot-odon said:

You could carefully try removing this shale using a sharp and, preferably, flexible needle, carefully prying away at it,

One day, when I will feel extra courageous, I will try...! Thank you for all the explanation, I learned a lot.

 

(And a Pratchett citation!)

[North]

8 hours ago, pachy-pleuro-whatnot-odon said:

 Macrospondylus 'Steneosaurus' bollensis seems the appropriate ID, with its carinae likely lying in wait underneath the overlying shale. You could carefully try removing this shale using a sharp and, preferably, flexible needle, carefully prying away at it, until more of the tooth is exposed. @belemniten

Posidonian Steneosaurus has been reassigned to Macrospondylus? I did not notice.

[rocket]

2 hours ago, North said:

Posidonian Steneosaurus has been reassigned to Macrospondylus? I did not notice.

always in discussion...

 

 

Macrospondylus.pdf

[belemniten]

Nice tooth! 

Everything has already been said here about the determination.

The best way to prepare them is with a sandblasting machine and a stylus (I also offer customised preparations). However, you could also try using a scraper or needle and expose the tooth a little. The enamel usually separates very well from the surrounding rock.

[Laleja]

6 hours ago, belemniten said:

The enamel usually separates very well from the surrounding rock.

It DID separate when I split the stone, right. Maybe I'll try... it's just so tiny.

Thank you so much!

[pachy-pleuro-whatnot-odon]

1 hour ago, Laleja said:

It DID separate when I split the stone, right. Maybe I'll try... it's just so tiny.

Thank you so much!

 

Get yourself either a magnifier lamp or magnifier headband. This should help in prepping small fossils

[Laleja]

22 hours ago, pachy-pleuro-whatnot-odon said:

Get yourself either a magnifier lamp or magnifier headband. This should help in prepping small fossils

...and steady hands!

[Paolo997]

Hi, I'll join the discussion too

First of all I would like to point out that I am not an expert but simply a great enthusiast. I have been collecting fossils in the Ohmden/Holzmaden and Solnhofen/Eichstatt regions for 3 years. I'm still learning too. I confirm it's Steneosaurus tooth. I also found one last year in Ohmden. here is the link to my discussion with post-preparation photos. 

https://www.thefossilforum.com/topic/132864-ohmden-tooth-id/#comment-1418187

 

I found my tooth while splitting a rock and it stuck out about 20%, a bit like yours. to prepare it I used a very sharp cutter and with LOTS of patience I delicately removed layer after layer. it was my first preparation and fortunately it went well with no cracks (unfortunately i can't say the same of my giant Ichthyosaur tooth, but this is another story ). I found very useful to first make the rock softer with water, before scraping. Ichthyosaur teeth are very different. chubbier, straighter and with very visible streaks (as in this case) but less "three-dimensional". I was able to find some of them in Ohmden too.  I'm not an expert in preparations, but from the little I've been able to do I can tell you that the fundamental rule is not to put pressure on the tooth while preparing. they tend to explode into a thousand pieces 

I hope I have been helpful

 

[Laleja]

Thank you for encouraging me and sharing your preparation experience! I read your thread - what a very nice find. Congratulations to your success in preparing it. I imagine how exciting it must have been...