Colonial Coral or Worm Tubes or Something Else?

[Pippa]

My daughter and I took advantage of the unseasonably warm temperatures over Christmas to go rockhounding at a nearby beach.

She found what looks like a colonial corals. At first I thought they might be rugose, but they're smooth, not wrinkled and each corallite has this round "cap" on.  So then I thought of syringopora, but I think for that the corallites are too large. Also, the individual corals grow/point into all different directions. That made me think that they might not have grown together, but were just deposited into a heap.  What do you all think?

 

 

detail of the area just below the darkish top:

 

small vug on top of one of the corals, with a bit of the structure showing:

 

[Rockwood]

The irregular pattern of holes is similar to that seen associated with worm feeding. Possibly this represents a worm burrow ?

[Pippa]

7 hours ago, Rockwood said:

The irregular pattern of holes is similar to that seen associated with worm feeding. Possibly this represents a worm burrow ?

I  never thought of worm burrows. Hmm.... these tubes look so uniform and the vug clearly shows structure inside. I've googled "worm burrow fossils" and have not come upon anything like this, many also show a ring patterned outside.  

Which "irregular pattern of holes" do you mean?  Photo 1 with the holes on top, or photo 2 with the side detail?

 

P.S. I edited the title to reflect the possibility of this being burrows. Hopefully this will bring some experts to this thread.

 

[Rockwood]

Incredibly I found the files from when I posted this cornulites trace. (thought to be at least) 

[Pippa]

23 hours ago, Rockwood said:

Incredibly I found the files from when I posted this cornulites trace. (thought to be at least) 

Nice!

 

Your second and third photos, show rocks with empty wormholes, yes, I understand those are trace fossils.

I'm not quite sure what I'm looking at in your first photo though. 

Not only is the burrow in the first photo at least 3 times the diameter of the burrows in the second and third photos, it also seems to have a fossilized worm in it?  As it's fossilized, it must be its outer tube dwelling that's visible, no? If so, why do you call it a trace? 

 

Regarding my rock, it seems to me what's visible are the worms outer tubes, their dwellings, not their burrows. Surely casts of burrows wouldn't look so smooth and uniform?

A propos: smooth:  the tube shapes on my rock are that. They are really smooth. Why? All googled pictures of tube worms, and their burrows show pronounced rings along their length...

Sigh. I think I'm more confused now about my rock than before.

 

[Rockwood]

My example was chiseled from a boulder in pieces. It was the position of the cornulites (worm tube) that fit what another member suggested looked like worm feeding traces.

The fact that worms are nearly pure muscle allows them to go from short and fat to long and thin when extended to feed. It's the two states that I propose are shown.

[Pippa]

10 hours ago, Rockwood said:

The fact that worms are nearly pure muscle allows them to go from short and fat to long and thin when extended to feed. It's the two states that I propose are shown.

 

Aha, that makes a lot of sense. 

In your 1st photo is this a worm steinkern visible inside the burrow?  If yes, that is really cool.

 

As to my fossil. I'm still not sure what I'm looking at. 

Maybe I don't understand the terminology in regards to worms, burrows, tubes.

 

Anyone with some knowledge, please help to clarify my thinking by answering the following: 

 

Are the following statements correct or wrong or somewhere in between, and if wrong, why?

1. There are various types of worms: burrowing worms, boring worms, tube worms and maybe/probably others and they differ widely in their 'life styles".  
2. Burrows and tubes aren't interchangeble terms. 
3. A burrow is a tunnel that a soft bodied worm creates by tunneling through mud or softish stones such as lime/sand stone.  
4. Burrows are trace fossils.
5. A tube worm's tube is its protective shield that the worm's body creates around itself. (Similar to fossilized coral, where the polyp within is not preserved.) 
6. Worm tubes are regular fossils, not trace fossils. 
7. Tube worms do not tunnel through mud or rock.
8. Tube worms anchor themselves by submerging themselves in sediment, with only the top of the tube showing.
9. Tube worms feed with featherlike / tentacle like parts which they pull back into the tube for protection. (Again, silmilar to coral polyps.)  

Thanks to everyone who helps to educate me.  I need it badly and appreciate it. 

[Rockwood]

36 minutes ago, Pippa said:

In your 1st photo is this a worm steinkern visible inside the burrow?

I think it is a worm tube steinkern. It must be in sediment with the pattern of small holes representing feeding episodes toward the surface as I see it at least.

I think you have these answers about right. 

I'll be watching though. 

[Rockwood]

It just occurred to me that I never explained that my thought on the post has the larger round shapes being a burrow trace (full diameter of living space) and the smaller holes being the extended feeding traces.

[Mark Kmiecik]

I'd like to see more photos like the first one from all around the other sides of the specimen.

[Pippa]

Hi Mark, 

Glad to see you on this  thread.

I will try to take some more pics tomorrow. As I don't have any special lighting, my photos turn out better when I take them during daylight.  

[Pippa]

6 hours ago, Rockwood said:

It just occurred to me that I never explained that my thought on the post has the larger round shapes being a burrow trace (full diameter of living space) and the smaller holes being the extended feeding traces.

Thanks for posting this, Rockwood.  

Let's see if I understand you correctly:

 

Do you mean with "the larger round shapes" the round darkish ends or what I called "caps" above? These are the burrow traces? And the irregular holes are feeding traces where extended "feathers" or tentacles left holes behind?

If that's what you mean, then the stout round parts that lead up to the dark round ends or caps are then the fossilized worm tubes?

Like so:

 

[Rockwood]

4 hours ago, Pippa said:

If that's what you mean, then the stout round parts that lead up to the dark round ends or caps are then the fossilized worm tubes?

My thought was it being a trace fossil (altered sediment). The fossil representing separate behaviors.

Keep in mind that I could be way out to lunch with the whole idea.

[Pippa]

18 hours ago, Rockwood said:

My thought was it being a trace fossil (altered sediment). The fossil representing separate behaviors.

Keep in mind that I could be way out to lunch with the whole idea.

Lol. If you're out to lunch, I must be out to breakfast, lunch AND dinner... 

Hopefully the additional photos will help to clarify things. I discovered details that I hadn't noticed before. 

I'll post them below.

[Pippa]

Mark, I took some more photos tonight (we had rain and fog in the morning, so alas, no daylight pics. The regular pics below aren't great as the pics get grainy in my low ambient light. But, while playing with my handy-dandy LED lighted clip-on microscope, I saw that the ends or "caps" aren't just smooth without detail, oh no, they are in fact covered in pores, so I took some more close-ups showing that. Hopefully that will help in identifying what we're looking at.

 

So here some more photos from various angles:

 

 

 

continued below.

[Pippa]

 

 

 

 

 

Rounded edge of end "cap":

 

 

[Rockwood]

I think, roast chicken, mashed potatoes and green peas would be nice.  

[Mahnmut]

Hi,

I hope that doesn´t sound offending in English, but in German "adding ones mustard" means giving ones opinion, rather unasked for:

 

especiallythe  three last pics look to me like something with a quite regulary porous structure, like for example coral or sponge, that has been bored into less regularly by something else, for example a worm. That could also explain the rounded "caps" in the first pics as more or less eroded  branches.

Just what it looks like to me without knowing anything about its age or palaeoenvironment.

Regards,

J

 

[Rockwood]

1 hour ago, Mahnmut said:

I hope that doesn´t sound offending in English, but in German "adding ones mustard" means giving ones opinion, rather unasked for:

Personally I consider it rude to not offer an opinion to someone one believes could use it. If it works anywhere it would be around here.

[Pippa]

6 hours ago, Rockwood said:

I think, roast chicken, mashed potatoes and green peas would be nice.  

Rockwood,

Good morning!

Personally I prefer coffee and a croissant for breakfast. 

But be my guest. 

 

[Rockwood]

On 1/10/2020 at 2:42 AM, Rockwood said:

way out to lunch with the whole idea.

[Pippa]

2 hours ago, Mahnmut said:

I hope that doesn´t sound offending in English, but in German "adding ones mustard" means giving ones opinion, rather unasked for

 

J, dein Senf ist immer willkommen. Schönen Dank! 

2 hours ago, Mahnmut said:

especially the  three last pics look to me like something with a quite regular porous structure, like for example coral or sponge, that has been bored into less regularly by something else, for example a worm. That could also explain the rounded "caps" in the first pics as more or less eroded  branches.

Just what it looks like to me without knowing anything about its age or palaeoenvironment.

I find my fossils in Lake Michigan, north of Chicago. Silurian bedrock around here, devonian a bit further north. Glacial drift brought and wind/wave action still bring material from up north to my area, so devonian material is a possibility.

I find a variety of halysites , favosites and solitary rugose corals, among plenty of other corals, brachiopods and bryozoans and what probably are sponges, just as yet unidentified.

 

This thing looks really different though from anything I've ever found. 

The capped drum shapes are odd and I can't find anything resembling them when googling or when looking at the Geological Surveils of Illinois and Wisconsin etc.

On my searches I've come across scholarly articles that I hoped would be helpful, just to find I don't have access.

Looks like I am back on square one...

 

[Pippa]

1 hour ago, Rockwood said:

On 1/10/2020 at 1:42 AM, Rockwood said:

way out to lunch with the whole idea.

 

Better to be out to lunch with an idea than not having any ideas at all. 

Plus, you make me laugh. Always a good thing.

 

[Mahnmut]

Or any lunch either.

Thanks Pippa for the contextual information.

I am definitely not informed enough to ID this piece, but I am relatively sure on two things (as you may also be after taking the high res photos):

-The whole thing looks like a grown structure, not a steinkern of a burrow or something like that. (Sponge, Coral or else??)

The "caps", in the green circles in my version of the pic, may be typical for that kind of organism or they may be eroded remnants of longer protuberances.

The pits that where visible in the low-res pic, circled red in my version, appear relatively irregular and may be secondary, maybe traces of some other organism?

Best Regards,

Jan

 

 

[Mark Kmiecik]

19 hours ago, Pippa said:

Petrified puppy head. That's my final answer.  But seriously, the additional photos only make it harder for me to ID.