Jump to content

Tiny Devonian Echinoderm and possible Bryozoans


Greg.Wood

Recommended Posts

All specimens come from the Devonian aged Arkona formation.

 

1. Echinoderm, possibly a blastoid

Tried taking another pic...still not quite sharp

_16C6994.JPG.5c8b260972833ca8ab8bbf9b39810f87.JPG

_16C6965.JPG.794512cf9cd38a81d703401260bd8697.JPG

 

2. Unknown, possibly bryozoans (remainds me a bit of Evactinopora)

_16C6955.JPG.28558a3717fda61d17c7c1cff75269ff.JPG

_16C6950.JPG.39fcc5b184a53b20a88121b9bca74946.JPG_16C6953.JPG.2d6c4bff3878d1a27a9a2c9ba5c77896.JPG_16C6954.JPG.042b55f0ce541c7e4f5a4e124cda972a.JPG

 

3. Unknown, probably the inner structure of ostracods

_16C6985.thumb.JPG.0604281d4efb00043843ff9eff62e546.JPG

With these being the outer shell:

_16C6984.thumb.JPG.94cd19f52b0a189f4c0b27608020a4b6.JPG

 

4. I posted these about a month ago but I don't think we figured it out. Now I am pretty sure they are scaphopods.

5a6e2ab668e36_Mollusca-Scaphopoda(2).thumb.JPG.1307cb2ba2703491aeb33996006b1a51.JPGMollusca-Scaphopoda.JPG.569f0fda7ae2d69f0ced3abb9e358ed5.JPG

Link to comment
Share on other sites

2 minutes ago, Al Dente said:

Number two look like crinoid columnals.

Could be, but the shape seems very irregular. Maybe preserved a different way or very worn out. These are the common crinoid bits I'm finding for comparison:

_16C6967.thumb.JPG.64ebcf7236899cce95b0f899bfab6aa5.JPG_16C6969.thumb.JPG.b661b82056cfded7cf7e0087d9b80bdb.JPG_16C6979.thumb.JPG.36c97afcc9233ceb85bd5fbab93eed48.JPG

Link to comment
Share on other sites

The crinoid ossicles usually have a good degree of symmetry, so the second picture in the initial post doesn't quite give me a crinoid columnal vibe. I'll have a look in my literature...

 

They seem to most closely resemble crinoid arm bits. I've seen a few that have that kind of irregular-radial nubs appearance. This is just a best guess based on these pictures, and I'm still uncertain.

...How to Philosophize with a Hammer

 

 

Link to comment
Share on other sites

I'm pretty sure that the first one (1) is a blastoid calyx, although your pictures are a bit blurry.
 The second ones (2) have patterns that make me think they might be crinoid columnals, as it was said by Eric really right, according to the central hole which might be the lumen. Try to compare them with the specimens close to yours from the picture below.

img47.thumb.jpg.c27326ed25b242723d035c0e14b2b750.jpg

(It don't has anything related to Evactinopora, I'm affraid.)

 

Nice pictures BTW, thank you for them.

The last three ones shows: 1 - columnals, 2 - spines and brachials, 3 - arm fragments, probably of biserial arms. (in my understanding)

 

 

 

 

 

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

Thomas Mann

My Library

Link to comment
Share on other sites

Pic 1 is definitely a Blastoid, not sure of species tho as it is way small. Edit: After another look I want to say Heteroschisma sp.

 

Pic 3 are not Ostracod interiors, they are a different genera and species from those in Pic 4. I think those in Pic 3 are in the family Hollinidae and possibly genus Ctenoloculina (of which there are 5 species listed as known from the Arkona Formation. Attached is a .pdf from the University of Michigan that may help in identifying what you have.

 

Pic 4 might be the ostracod species Ponderodictya punctulifera which is fairly common.

 

Makes me want to go "fishing" again in the screenings I have from Arkona. :)

 

 

 

OSTRACODS OF THE FAMILY HOLLINIDAE FROM THE ARKONA SHALE.pdf

-Dave

__________________________________________________

Geologists on the whole are inconsistent drivers. When a roadcut presents itself, they tend to lurch and weave. To them, the roadcut is a portal, a fragment of a regional story, a proscenium arch that leads their imaginations into the earth and through the surrounding terrain. - John McPhee

If I'm going to drive safely, I can't do geology. - John McPhee

Check out my Blog for more fossils I've found: http://viewsofthemahantango.blogspot.com/

Link to comment
Share on other sites

@abyssunder Thanks! I can see the resemblance between #2 on the original post and 8/9/10 on that plate. I'll get a clear shot of the blastoid tonight since the first one didn't turn out.

 

@Shamalama That pdf will be very useful, I'll have to start taking a closer look at these ostracods. I sifted through 4 buckets of mud this winter so I'll have to post everything I found at some point.

Link to comment
Share on other sites

the ostracods might even be useful paleo-ecologically speaking(e.g.presence of Thuringian ecotypes,but also valve ratios,possible presence of instars,velar dimorphism)

 

 

 

Link to comment
Share on other sites

Attached are some crinoid sections( all photos are 5.5x8.5 mm), which I assume are holdfast sections from the mississippian,and Ordovician similar to yours. very nice finds I will have to visit that area. Packy

Crinoid stem section-Miss.New Providence-Scott Co.#37.jpg

Crinoid stem section-Miss.New Providence-Scott Co.#42.jpg

crinoid disc-Ord. Maysville Ky Kope-fairveiw.jpg

Crinoid stem section-Miss.New Providence-Scott Co.#23.jpg

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...