Algae ?

[Rockwood]

This rock was found in association with blasted rock that was used as rail bed fill. I have reason to believe that it is Ordovician in age based on the distinctive appearance shared with rocks that members have identified a different type of algae in. 

The strand of honey comb like shapes is about 2 mm long. I suspect it may be part of the net like structure in the rock whose morphology happened to be better preserved.

[ynot]

Sorry, I got nothing on this one.

[KimTexan]

The surface texture of tiny dot like clusters looks like Bryozoa to me. I have fossils with this on it from the Cretaceous.

Are you asking just about the surface dot clusters or about the mineral veins running through the rock too?

[Rockwood]

20 minutes ago, KimTexan said:

The surface texture of tiny dot like clusters looks like Bryozoa to me. I have fossils with this on it from the Cretaceous.

Are you asking just about the surface dot clusters or about the mineral veins running through the rock too?

I think you may have something there. I had sort of dismissed the idea thinking it lacked a substrate to encrust, but I guess Fenestrates do go back far enough to fit the assumed age.

There are signs of pressure dissolution, in the form of stylolites that seem to undulate in and out of the exposed surface in this type of rock. Perhaps these are bits that just happened to be exposed in the same manner ?

Between the pressure dissolution and the metamorphosis the mineral veins may not be identifiable unless the geometry of them is meaningful to someone.

[Innocentx]

I think @KimTexan is right about this being bryozoan. It was my first thought, too. 

24 minutes ago, Rockwood said:

I think you may have something there. I had sort of dismissed the idea thinking it lacked a substrate to encrust, but I guess Fenestrates do go back far enough to fit the assumed age.

Fenestrate would be my guess as well.

[Rockwood]

I just thought of these shots I took with the intention of making a post about stylolites. They are in the same appearing rock from the same rail bed. A bryozoan and the other algae I can't remember the name of are well exposed. 

Perhaps I'll see if my head is on strait with the stylolites at the same time.