Coral, Sponge or Bryozoan?

[I_gotta_rock]

I'm stumped. I've been collecting erratics off the beach along the Delaware Bay for the last six months and I keep coming up with mysteries. This specimen is 1" long. Unfortunately, because it is an erratic, all I can tell you is that rocks of this type wash down from the Appalachians all along the Delaware River and Bay til it reaches the Atlantic Ocean. They are Paleozoic, but I don't know enough of the geology from PA and NJ to narrow it down by rock type to a formation. Can't find a high enough resolution GEO Survey map, either. Other fossils in this type of rock are rugose corals, tabulate corals, bryozoa, and pinhead-sized crinoids, so big possible spread on the time frame. No trilobites yet, unfortunately!

 

I have a small id sheet from the Mahantango Formation and an ID book for the Middle and Upper Devonian of NY, but neither have anything similar. I posted on the FB group and got three people saying it was one of these (yeah, I knew that) but each thought it was a different phylum. Can I get a consensus on phylum, if not a genus here? Can anyone give me links to good reference material for my other mysteries?

[caldigger]

Come on Heather, you should know by now you need to put something in the shot for size reference.

I am not in the know on these matters but it does look quite nifty.

[Miocene_Mason]

Branching coral, like trachypora perhaps? in the underlying needmore shale it’s pretty common. Don’t know if it exist in the mahantango FM but I don’t see why not.

[Plax]

I was thinking Coenites but may be a mile off. Been too many decades since I was a PA resident.

[D.N.FossilmanLithuania]

Probably coral but not Coenites.  I see the other branch cross section below that makes me think that the rock belongs to coral reef association. 

[Tidgy's Dad]

I also think coral, scale may help a little but without knowing the age or origin it's going to be hard to identify to genus level. 

[Rockwood]

Someone has to take the bryozoan side.

I judge the size to be in range, and the sectional shape to be oval/round enough.

I don't believe coralites would grow in a way that would make the larger size evidenced in the shape below it relevant to an ID of the central character. 

[Fossildude19]

2 hours ago, caldigger said:

Come on Heather, you should know by now you need to put something in the shot for size reference.

I am not in the know on these matters but it does look quite nifty.

 

She says the specimen is 1 inch long.  

[I_gotta_rock]

3 hours ago, WhodamanHD said:

Branching coral, like trachypora perhaps? in the underlying needmore shale it’s pretty common. Don’t know if it exist in the mahantango FM but I don’t see why not.

Probably not Mahatango, looking at the rest of the matrix. The Mahatango stuff I have isn't white and it doesn't have the inclusions. It's red to grey and pretty uniform, at least in the Beltzvill, PA area, but I have been using it as a reference for narrowing things down a bit. What I need are some other references to compare from the Delaware River watershed in PA and NJ. I'm leaning away from coral, just because of the elongated, unsectioned holes(?) toward the top end of the picture seems it mightnot have been a straight branch originally. Small, round holes at one end and elongated ones at the other that look more like same kind of holes cut at a different angle

[erose]

Ok here is my two or three cents...

 

Matrix is probably NOT Mahantango. Lower Devonian or maybe Onondaga would be my SWAG.

 

Scale bar is needed. You said it was about an inch long but what we need is to see how big those little openings actually are. The zooeciums of bryozoans are always tiny. A fraction of a millimeter, not bigger. The smallest corralites are still at least a millimeter across.

 

Put a scale across the openings and let us know what you measure.

[Plax]

46 minutes ago, I_gotta_rock said:

Probably not Mahatango, looking at the rest of the matrix. The Mahatango stuff I have isn't white and it doesn't have the inclusions. It's red to grey and pretty uniform, at least in the Beltzvill, PA area, but I have been using it as a reference for narrowing things down a bit. What I need are some other references to compare from the Delaware River watershed in PA and NJ. I'm leaning away from coral, just because of the elongated, unsectioned holes(?) toward the top end of the picture seems it mightnot have been a straight branch originally. Small, round holes at one end and elongated ones at the other that look more like same kind of holes cut at a different angle

My feelings exactly regarding the holes. The elongated openings are almost longitudinal views. The typical exterior coral shaped openings look to be ground off if it is indeed a coral. The Berwick site in Fossil Collecting in Pennsylvania book has coenites white in shale instead of the leached away holes in the rock typical of Mahantango. You specimen's lithology has changed with diagenesis to chert so it will be tough to figure a formation short of a good index fossil.

[I_gotta_rock]

9 minutes ago, Plax said:

My feelings exactly regarding the holes. The elongated openings are almost longitudinal views. The typical exterior coral shaped openings look to be ground off if it is indeed a coral. The Berwick site in Fossil Collecting in Pennsylvania book has coenites white in shale instead of the leached away holes in the rock typical of Mahantango. You specimen's lithology has changed with diagenesis to chert so it will be tough to figure a formation short of a good index fossil.

And even if I did find a good index fossil in another rock, it would be impossible to know if they came from within 50 miles as the crow flies or 100 feet as the groundhog burrows of eachother.

[caldigger]

3 hours ago, Fossildude19 said:

 

She says the specimen is 1 inch long.  

Oh great now I'm going blind.

Just add that to my list of physical ailments and miseries.

[Plax]

http://www.geoffbroughton.talktalk.net/WrensNest/Corals/album/slides/Coenites intertextus 1.html

[Rockwood]

9 minutes ago, caldigger said:

Oh great now I'm going blind.

It will get worse by the time you finish processing how big that makes each zooid/coralite. 

[Rockwood]

2 hours ago, erose said:

The smallest corralites are still at least a millimeter across.

 

3 minutes ago, Plax said:

http://www.geoffbroughton.talktalk.net/WrensNest/Corals/album/slides/Coenites intertextus 1.html

Inconsistent ?

I thought there was a small amount of overlap.   

[Plax]

I posted the link in defense of the possibility that it was coenites. Was told it was not. (and of course I'm only guessing)

  And when you google coenites and look at pics there are some from the Mahantango. Not saying it is either coenites or mahantango but saying it's possible. I agree with one of the earlier posts that we'll never know for sure.

[I_gotta_rock]

Took it with me to my museum photo lab yesterday and tried o do a few, slightly better, quick pictures. Still cold be better, but been fighting chronic migraines the last couple days. This is what burning mysteries do it me. It would not be my luck to have an index fossil elsewhere on the same rock, but maybe this coral on the other side will help narrow it down.  I agree with @plax, that it looks similar. Also kind of looks like Striatopora, but again holes may be too small?

[FranzBernhard]

These things from the palaeozoic of Graz (Eifelium, Devonian), Styria, Austria are also called striatopora, I think. Field of view is 55 mm, so the holes are about 0.5 mm wide.

Franz Bernhard

[I_gotta_rock]

6 hours ago, FranzBernhard said:

These things from the palaeozoic of Graz (Eifelium, Devonian), Styria, Austria are also called striatopora, I think. Field of view is 55 mm, so the holes are about 0.5 mm wide.

Franz Bernhard

Looks like we have a match! Coral it is!