Three Ordovician Unknowns

[minnbuckeye]

these are three specimens collected in Fillmore County , Minnesota this summer. This is Ordovician. Beyond that, these were out of fallen rock and I can not narrow it down any  more.I keep looking at them, not really sure  I understand what they are. Soooooooooooooo feel free to comment on them.

1.  Looks crinoidal but is full of pores. So bryozoan masquerading as a crinoid cup? Or bryozoan covered crinoid cup?

 

 

 

 2. All I can think of is 2 brachiopod shells in apposition, but the linear structure in the middle confuses me. The hinge??

 

 

[Tidgy's Dad]

Number one - Bythopora? Is that possible in the formation? 

[minnbuckeye]

3. This may be nothing.  But I see a "stalk leading to a crystalized sphere. My guess is the stalk is not associated with the sphere but I hated to pitch it if it were something unique. Many cephalopods locally on cross section carry this crystalline appearance. And Isotelus fragments are often the color of the stalk

 

 

 

[Tidgy's Dad]

Maybe a pelmatozoan calyx infilled with calcite? 

Interesting. 

[FossilDAWG]

Regarding #1, although there are some crinoids that have a highly porous "shell", the lack of regular structure suggests to me that this one is a bryozoan masquerading as a crinoid.

I think #2 is an internal mold of a bivalve, seen edge on.  It could also be a Leperidita-type ostracod (again seen edge on), they can get to be quite large as well.

The "stalk" in #3 does not show any segmentation that I can see, which would be expected of a pelmatozoan (cystoid or crinoid) stalk.  I think the "stalk" is probably not organically related to the void with crystals.  The void could be anything from a hollow brachiopod to a crinoid or cystoid, there is no data (such as a glimpse of the exterior surface or an impression of the surface) on which to make a diagnosis.

 

Don

[Raggedy Man]

That middle one looks like a clam Caleb posted. I also have one from Fillmore County and Grant county. Ill see if I can dig up Calebs post.

[minnbuckeye]

I thank everyone for the responses. Looks like these can go into my rubbish pile instead of taking space anymore on my ping pong, I mean work table. It would be nice to see Caleb's clam.

[Innocentx]

Could the last one be lingula?

[Johannes]

The first one seems to be a coraline bryozoa colony, genera is hard to say. The second one reminds me to some types of Archaeogastropoda (Link), but not for sure (but no clam or brachiopod I think)

[NdijNus]

As for #1.), this is what iFound online:

Bryozoans were able to live almost anywhere: on a brachiopod shell, the side of a cephalopod, coating sea plants, or in an individual colony on the sea floor. Many fossils have patches of bryozoans on them. Bryozoans first evolved in the Ordovician and have persisted to the present day; they live in ocean habitats that are similar to those of Paleozoic seas.
 

iWas led here because iMyself found a crinoid stem that was covered in bryozoa! It had 1 little stub of a branch that was covered yet both of  the broken off stems, in the center, it was very,very clearly a crinoid! iLooked around the web and could find no other Bryozoan covered crinoid examples, only here!

iBelieve my insert above, explains it for both of us! iCan Only imagine that they must be at least somewhat rare since i’ve not been able to find any other examples, so iHope U weren’t serious about your rubbish pile, minnbuckeye! If so, from now on, send your rubbish to me! i’ll take it!!! 

[minnbuckeye]

@NdijNus, my rubbish pile is actually a large "sandbox" at a local nature center/zoo that provides children a chance to find fossils. I deposit a 5 gallon bucket in there every couple of weeks. Since you live close (Minnesota is God's Green  Country), visit the site and see if they are still there!!!!!!! 

 

Mike

[NdijNus]

minnbuckeye, 

ahhh, how wonderful of U to do that for children! iAm fond of children, as well, and try to nurture their interests in rocks/fossils! U simply must look up the story on Bridger Walker, P.O. Box 22141, Cheyenne, WY  82003. His Facebook page is:  BridgerStrong. He wants people to post pics of their fAve rocks/fossils to his page to keep him entertained during his recovery. Neither him, nor his family ever asked for rocks to be sent to him, just to share their pics for him to look at on his page, but once U hear his story, U want to send him rocks -nice ones!!! With so much demand for his address, his family made it public! iAm in no way related & do not know him. It was Only his story that grabbed me hook, line, & sinker! He saved his sister’s life by putting his Own self in very grave danger & was mauled for his bravery while his little sister remained unscathed!

 

...sO, somewhere out there a child might have the only other crinoid that’s known to be covered iN Bryozoa!!!  If anyone else comes across any fossil that’s very clearly something else but that’s covered iN Bryozoa, will U please post it here, er else post the link, er just let me know.

i’d like to find out how rare it is, as this page was, literally, all that iFound that had one pictured!!! 

 

Thank you, Fossil Forum!!!

i’ve been led here many times before, so i’m

very happy to finally be a member myself!

[Johannes]

On 25.7.2020 at 5:29 PM, NdijNus said:

i’d like to find out how rare it is, as this page was, literally, all that iFound that had one pictured!!! 

 

It's not that rare, bryozoans colonise nearly every hardground. Esp. finds of immurating bryozoans on other fossils in silurian and ordovician reef-assciated environments are quite common. Unfortunately, such fossils are not in the focus of the middle-of-the-road-collector, and often removed by preparation.

 

I remember a paper describing an in-vivo-settlement of (devonian/silurien?) bryozoa on brachiopods, if I find it I will post the reference here....