Georgian Bay Bryozoa

[Tidgy's Dad]

These bits are on the same piece of rock, kindly sent to me by the marvelous @Monica.

They are from the Etobicoke Creek, Toronto, Ontario, Canada and are Georgian Bay Formation which is Late Ordovician in age. 

I think they are likely bryozoa, but stromatoporoid might be possible for the first one and algae for the second.

They are found in a piece of rock that also contains Paupospira (was Lophospira) gastropods, crinoid stems and individual columnals, Cornulites flexuosus and Flexicalymene granulosa. 

The first one doesn't seem to have much depth to it. 1 to 2 mm at most. 

The second one is a stick !

Another stick :

 And what are the spiky toothy things? 

[Rockwood]

That first one looks a bit like bone to me. Any chance it's the head shield of an agnathan ?

[Tidgy's Dad]

3 hours ago, Rockwood said:

That first one looks a bit like bone to me. Any chance it's the head shield of an agnathan ?

Thanks for your reply.  The shape does look a bit one, doesn't it? 

But I don't think that's possible in this case.

I would wet myself with joy if it were. 

[Rockwood]

[Tetradium]

14 hours ago, Rockwood said:

Prasopora.............. One look like maybe very well worn bryozoan while another is conodont jaw. 

[Tidgy's Dad]

12 hours ago, Tetradium said:

Prasopora.............. One look like maybe very well worn bryozoan while another is conodont jaw. 

I don't have Prasopora listed for this formation, what's your source, please? 

None of these look like that genus anyway.

I have several scolecodonts from the formation, but no conodonts. Which one do you think is a conodont and why?  

[Tetradium]

Prasopora and some of the other bryozoan frequently encrust hard substances. If you have seen some of my image gallery you can see the younger colonies and mature colonies. Younger colonies tend to be flatter due to worn brachiopod/bivalve shells. I hadn't does any extensive researches on encrusting or most other bryozoan - the annoying thing is most bryozoans except for Batostoma tend to look the same under my digital microscope. And even I found out earlier this year that Batostoma tend to start out as encrusting which matures into stumpy rugose versions. 

\

I'm just using the Minnesota fossil book for a example to show the diversity in shapes of conodonts. I hadn't found any - they tend to vary wildly in the # per layer and unfortunate for me they're very low density in Decorah shale while as for the other method I will have to use strong acids to dissolve limestone to find them. Strong acids are expensive online and I don't have time currently to try to make my own - I checked food store - all the vinegars are of the weaker acid kinds. 

3 hours ago, Tidgy's Dad said:

I don't have Prasopora listed for this formation, what's your source, please? 

None of these look like that genus anyway.

I have several scolecodonts from the formation, but no conodonts. Which one do you think is a conodont and why?  

After all conodonts teeth also worn down as well too. 

[Tetradium]

4 hours ago, Tidgy's Dad said:

I don't have Prasopora listed for this formation, what's your source, please? 

None of these look like that genus anyway.

I have several scolecodonts from the formation, but no conodonts. Which one do you think is a conodont and why?  

Here's a few digital microscope pictures of the most fine hash pieces of limestone in Decorah formation - you can see what I mean? I'm not pushing you to id anything anymore - just show you an example of what I faces and I'm obviously not a specialist.  

 

I'm not trolling you - I admits I'm a poor student and have so much more to learn - already I have learned more about fossils in half a year than I did for 20 years. Right now I'm pretty busy and tired with my part time job and is focusing on id some St Pierre formation ammonites for now ok.  

[Kane]

Adam, if you don't have it already, Bill Hessin's book is ideal. PM coming.

[Mainefossils]

@Tetradium, I don't think that it is necessary to use strong acids for preparation. Generally, this destroys details on specimens. In most cases, a 5-10% solution of acetic acid is preferable. Household vinegar is often used, which is a 5% solution of acetic acid. This will most likely take a long time, around a couple months, but it will give the best results. Happy hunting! 

 

Regards, 

Asher

 

 

[Tetradium]

1 hour ago, Mainefossils said:

@Tetradium, I don't think that it is necessary to use strong acids for preparation. Generally, this destroys details on specimens. In most cases, a 5-10% solution of acetic acid is preferable. Household vinegar is often used, which is a 5% solution of acetic acid. This will most likely take a long time, around a couple months, but it will give the best results. Happy hunting! 

 

Regards, 

Asher

 

 

 Thanks for the information.  That means it will have to be in a container with lid to prevent evaporation of water. 

[Tidgy's Dad]

Mr. Hessin's book is marvelous,. 

The first unknown looks a bit like the coral Protaraea which he expects is found in the Georgian Bay Formation. It has the right seabed encrusting, but thin nature, yet I rather think the 'corallites' are too small.