FMF - Friends of Minerals Forum, discussion and message board

[Elisha Paul]

Hello all! So I’m a 37 yr old guy from NJ. My dad found these on Anticosti Island in Canada back in the 1970’s. Can anyone tell me anything?!

[alfredo]

As Anticosti island is all very ancient sedimentary rock, Ordovician and Silurian, a time when there wasn't much life on land, your rocks would pretty much have to be some sort of marine fossil. Hopefully some other member here will recognize them for you. (Most of us here know more about minerals than fossils.)

[Pete Richards]

Alfredo is off to a good start. It can be added that vertebrates were rare and extremely primitive at this time. Tube shapes suggest straight nautiloid cephalapods, but one would expect them to have chambers, and to be rigorously straight, which these are not. I'm not familiar with the Anticosti fauna, but I would guess that these were sponges. Many sponges of about that time had silicious "skeletons" and often became silicified themselves. I wonder if these are similarly preserved.

By the way, I was a paleontologist studying Ordovician brachiopods before I returned to my greater love!

[Riccardo Modanesi]

I think those small colourless crystals are very interesting! It might be calcite or somthing similar, but a deeper observation should be done,
Greetings from Italy by Riccardo.

[Jmiles]

I would take a guess at a coral and crinoid segment. They have been replaced and infilled, I would guess by silica and unfortunately this loses much of their texture. I wouldn’t think you could identify it any further than that. Below are some Google images showing textures and crinoidal segments that are similar to your photos. Hope this helps.

[Jmiles]

Crinoidal segments

[Jmiles]

Rugose coral

[Volkmar Stingl]

Hard to tell from pics what this is, but for sure these are NOT corals or crinoids. None of the characteristic features of these are visible. Also look at the size! For me, it looks like sponges, like Pete says. But I wouldn't like to decide without holding in my hands.

[Jmiles]

Like I said above they have been significantly altered, likely silicified that ultimately makes you lose any characteristic features. The sizing is plausible too.
Peer reviewed literature would suggest evidence for reefs preserved on Anticosti Island. Whether you decide they are sponges, or corals and a crinoid segment as per my interpretation, both would point towards a similar formation environment - a reef.
Elisha, hope that helps. It might be worth Tweeting a photo, there is a huge geology community that commonly identifies things for the general public.