Follow up on Hexactinellid sponge roots

[Shamalama]

About eight years ago I posted about some odd fossils that I found in the Keyser formation limestone and the consensus was that they were roots of Hexactinellid sponges (glass sponges).  @piranha dug up some pretty good evidence that these are indeed from Hexactinellid sponges.  I recently visited the quarry again over my Christmas break and found more examples. I'm wondering if there are some fresh takes on what these may be and if anyone has found something similar?

 

For reference, these come from an old quarry near Mapleton, PA and are from the Keyser formation which is thought to straddle the boundary between the Silurian and Devonian periods. The layers they were found in were close to layers of the Tonoloway formation which is Upper Silurian in age.

 

Specimen #1 - This is the most interesting example I've found as the threads all seem to come from a central area and radiate out. Also note that they are layered and some have hook like endings.

 

Specimen #2 - This is a large plate with many clusters of these threads criss-crossing each other, but all in relatively same direction.

 

 

Specimen #3 - This is the first example I have that is associated with any other fauna. The Brachiopod is a small Atrypa reticularis

 

 

Thanks for looking and any suggestions are welcomed.

 

 

[Fossildude19]

I've got nothing to add here, other than these are incredibly cool and very interesting looking. 

[TqB]

Same as Tim, I'd still go with hexactinellid root tufts. Here's a closeup of the specimen of "Hyalostelia" I posted originally, from the lower Carboniferous, UK. They crop up quite often here - the filaments have variable diameters from specimen to specimen, maybe from different species but without the main sponge you can't be sure.

 

1cm long scale

 

 

[Archie]

Nice find! I was searching the net high and low a few days ago for the name of specimens of these from the Visean of the UK and eventually got to Hyalostelia, was about to give up and ask you several times @TqB! Wish I'd just waited a few days!  

[TqB]

17 minutes ago, Archie said:

Nice find! I was searching the net high and low a few days ago for the name of specimens of these from the Visean of the UK and eventually got to Hyalostelia, was about to give up and ask you several times @TqB! Wish I'd just waited a few days!  

 You could put them on here (and/or another thread) as Shamalama is asking about anything similar - I'd like to see them too! By the way, "Hyalostelia" used for the root tufts is a form genus - though it is also a formal genus of whole sponges that needs the body spicules for ID. 

[Shamalama]

3 hours ago, TqB said:

Same as Tim, I'd still go with hexactinellid root tufts. Here's a closeup of the specimen of "Hyalostelia" I posted originally, from the lower Carboniferous, UK. They crop up quite often here - the filaments have variable diameters from specimen to specimen, maybe from different species but without the main sponge you can't be sure.

 

1cm long scale

 

 

Thanks Tarquin @TqB. Never hurts to rehash a topic every now and again.  Your pic looks very much like the first specimen I posted above. Rounded fibers, while the other specimens have finer fibers.

 

I have spent many hours looking through books and reports to try and find any mention of fossils like these with no luck. The only sponges that are well known from the Keyser formation are Stromatoporoids and they form mounds. I can't imagine they would need roots to hold them in place.  I think if these roots occur elsewhere in the Keyser formation they may be overlooked as trace fossils.

[Archie]

22 minutes ago, TqB said:

 You could put them on here (and/or another thread) as Shamalama is asking about anything similar - I'd like to see them too! By the way, "Hyalostelia" used for the root tufts is a form genus - though it is also a formal genus of whole sponges that needs the body spicules for ID. 

Thanks Tarquin that's good to know! For a long time I thought they were brachiopod spines that had been sorted together by currents. I couldn't put my hands on any specimens of the filaments there but have a couple of body portions a friend ID'd as Hyalostelia smithii, I'm sure a have a spicule somewhere too.   

[Archie]

Heres the possible spicule about 5mm across next to a Petalodus that split out badly I'm hoping to save. 

[TqB]

17 hours ago, Archie said:

Heres the possible spicule about 5mm across next to a Petalodus that split out badly I'm hoping to save. 

 

Those body fossils are beautiful, we just don't get them laid out articulated on a surface like that in my area - everything has to be sectioned.

Hyalostelia is a good bet for them but unless your friend is a sponge specialist it's good to be cautious, sponges are very tricksy!

 

I think your spicule (if it is one, which it certainly looks like) is a heteractinid, not hexactinellid. They're calcareous sponges rather than siliceous and are characterised by spicules like that with basic hexagonal symmetry i.e. six rays in one plane (though there can be more or less). (In hexactinellids, the six rays (when they have them) are arranged 3D, on three axes at right angles to each other.)

 

It may be Tholiasterella gracilis Hinde which has been found in the Lower Limestone of Ayrshire - 5mm is about as large as they get.

 

They're a pleasingly weird (and generally quite rare) group which@Spongy Joe first told me about. Here's a section of one of mine from Co. Durham, which is characterised by mostly five rayed spicules. The largest is 3mm.

 

 

And probably the most famous heteractinid, Astraeospongium - link to  one I bought: -  Astraeospongium 

 

 

Apologies to Shamalama for hijacking the thread! - heteractinids don't have root tufts but they can occur in the same beds with hexactinellids.

 

 

[Archie]

That's brilliant Tarquin thank you that's very helpful! And yes sorry for hijaking your thread Shamalama! Those body fossils are from the Blackhall Limestone of the Lower Limestone Formation in Fife which the Dockra Limestone of Ayrshire has now been correlated with, although there are a few other limestone beds in the Lower Limestone Formation in both counties as well. That pic of the possible spicule isn't very good but that looks very much like it, it does have a raised bump in the centre as well. That section of them is brilliant! 

[Kato]

22 hours ago, TqB said:

 You could put them on here (and/or another thread) as Shamalama is asking about anything similar - I'd like to see them too! By the way, "Hyalostelia" used for the root tufts is a form genus - though it is also a formal genus of whole sponges that needs the body spicules for ID. 

@TqB

 

With no intent to hijack this thread but to add another root tufts specimen. This one is from the lower Pennsylvanian, Gobbler Formation in the Sacramento Mountains of New Mexico. All available studies of the area and formations list only 'sponge spicules' and no reference to any specific sponge types. I was struck with how similar the ones I found were to the ones you posted from the lower Carboniferous.

 

 

[TqB]

@Kato Fine specimen - and it has pretty much the same bryozoan fragments as in my piece too (though you can't see them there - mainly fenestellids).

[Shamalama]

Guys this is great! No worries about highjacking anything as you are just giving me more evidence that what I have are sponge roots. I will have to do more exploring at the site to see if I can find body fossils.

[Shamalama]

Ok, I found a paper about sponges in Tennessee:

 

Demosponges and Hexactinellid Sponges from the Lower Devonian Ross Formation of West-Central Tennessee
Author(s): J. Keith Rigby and Craig R. Clement
Source: Journal of Paleontology, Vol. 69, No. 2 (Mar., 1995), pp. 211-232
Published by: Paleontological Society
Stable URL: http://www.jstor.org/stable/1306253

 

And it has pictures of specimens that are very close matches to the first specimen in my pics at the top of the thread. Still nothing on the other, thin sheet like specimens but this is progress.

 

Unfortunately it seems J.K. Rigby passed away in 2011 so I can't ask him for an opinion on my findings.

 

Figure 4

 

Pic 11

 

Description of the figure

 

Figure 12

 

Description of figure 12

[TqB]

2 hours ago, Shamalama said:

Ok, I found a paper about sponges in Tennessee:

 

Demosponges and Hexactinellid Sponges from the Lower Devonian Ross Formation of West-Central Tennessee
Author(s): J. Keith Rigby and Craig R. Clement
Source: Journal of Paleontology, Vol. 69, No. 2 (Mar., 1995), pp. 211-232
Published by: Paleontological Society
Stable URL: http://www.jstor.org/stable/1306253

 

And it has pictures of specimens that are very close matches to the first specimen in my pics at the top of the thread. Still nothing on the other, thin sheet like specimens but this is progress.

 

Unfortunately it seems J.K. Rigby passed away in 2011 so I can't ask him for an opinion on my findings

 

Good stuff! So some at least may actually be sponge bodies with monaxonid spicules, rather than just root tufts. I think that would fit the sheet like ones too - we really need a specialist. Joe @Spongy Joe would be able to help but hasn't been on here for a while.