ID Help

[David M]

Hi,

 

I'm not a collector of fossils. I found this about 20 years ago. It was from the Niagara escarpment at Inglis Falls just outside of Owen Sound Ontario Canada. According Wikipedia the escarpment's caprock is dolomitic limestone and is composed of an outcrop belt of the Lockport Formation of Silurian age. I thought it might be a winged insect but if it is Silurian or Devonian maybe a water based creature. I'm not sure if it is a wing on top or part of something else. There appear to be a few small and very small mollusc shells embedded in the rock although they aren't clear in the photo. In the side strata there is quartz as well as other layers including a dark/black layer.

 

Whatever it is appears to be missing the head. There does appear to be another leg on the rock top as well.

 

Thanks for you kind assistance.

 

Best Regards,

David 

[hemipristis]

 

I looked up the formation on the USGS website. The Lockport Fm is subdivided into several members, and this one sounds like a combination of these two:

"The Niagara Falls Member is a gray to buff, biohermal grainstone, the Ancaster Member is a buff, thin-bedded, fine-grained, chert-rich dolomite". The quartz that you note is likely in the form of chert.  Fossils mentioned as occurring in the formation are corals and stromatolites (algal mounds).

 

I can see what you describe as "legs".  They do indeed look like it. Being marine strata, and given the age, I think we can rule out insect. Trilobites (and their close relatives) were the only creatures with legs at the time, and they did not have carbonate carapaces. In light of the this, I think what you are looking at are either branching bryozoans or fine branching corals

[David M]

Thank you for your reply and insight. At Craigleith, which is on the shore of Georgian Bay and not too far from where this was found, there is a shale deposit that has a lot of Trilobite fossils. What is cool about this one is what I thought was a leg is 3D and not flat. I'm not sure if that is true of all coral fossils but that part sticks out of the rock a bit and still has what may be it's original shape. I appreciate the fact that I now know it's age and identity. Thanks again for solving this mystery for me.

[Ludwigia]

My impression is that your "leg" is a branching bryozoa.

[Rockwood]

1 hour ago, hemipristis said:

I think what you are looking at are either branching bryozoans or fine branching corals

Do you suppose brachiopod spines might make the list ?

[David M]

Thank you both for your insight. I had to search bryozoa and brachiopod and look at images of their fossils to understand the information that you are providing. From what I can see the fossils can be quite similar so it could be either of these or coral. I'm very pleased with all of the information and finding out the geologic period. Thanks again!