My Last Hunt of the Season

[minnbuckeye]

During our last warm spell in November ( a high of 40 may not sound warm to you southerners), I took the opportunity to collect a few buckets of Decorah Shale to process during the cold snowy month of December. Here are some of the fossils found. Nothing too exciting, but fun to find!! @Tidgy's Dad, I would be pleased if you could assist me with my attempted IDs!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! And if there are some that you do not have yet, let me know and I will see about sending. 

 

1. I suspect Platystrophia extensa

 

 

 

 

2. Sowerbella minnesotensis. pedal valve above convex, brachial valve below concave

 

 

 

3. Sowerbella curdsvillensis. 

 

 

4. 

 

 

5. Rostricellula colei has far less costae than the one above and the costae are broad and smooth. 

 

6. Pycnocrinus are prevalent in the Decorah, but mostly small partial stem pieces

 

7.  Endoceras are the most common cephalopod I encounter in this formation, so the Isorthoceras was a welcome find.

 

8. Interior pedal valve of Strophomena filitexta, showing the well developed ridges for the large muscle attachment.

 

9. Unknown Strophomena interior pedal valves? At 2 cm wide and lacking the ridges of S filitexta, I am guessing Furcitella scofieldi.

 

 

10. The gumdrop bryozoan, Prasapora conoidea, has always been an enjoyment to find. They come in many sizes and shapes.

 

 

 

 

 

The next one has me a bit confused. Normally Prasapora are NOT attached to anything and show the obvious growth rings underneath. This one obviously is attached to a Strophomena leading me to wonder if it is a sponge or another species of bryozoa instead. Thoughts are welcome.

 

 

11. The Decorah Formation yields many Hesperorthis tricenaria. The pedal valve is easy to identify with its  beak and its triangular delthyrium.

 

 

It is the brachial valve that I am not sure of. This is my guess to its identity. Very flat with similar ribbing to the pedal valve

 

 

Here is a sample that contains what I think are both pedal and brachial valves

 

 

12.  The solitary rugosa coral, L. profundum, is found every time I hunt the Decorah. Here is a nice specimen in association with a few Sowerbella.

 

But this particular hunt provided me with two unknowns. First, is this a colonial rugosa or just 2 solitary L. profundums side by side. If colonial, I can not find any mention of a species name.

 

The second odd coral is this one. Very small and appears worn even though the matrix it popped out of was not

 

 

13. Many species of branching bryozoa are commonly found both loose and in matrix.

 

14. Pionodema subaequata at the top and Doleroides pervetus below.

 

 

 

 

15. These two are 3cm by 2 cm, leaving me to think an interior and an exterior surface of a brachial valve of Strophomena septa.

 

 

The size of this one is 2 cm by 1.5 cm. This pedal valve is quite raised, so I am suspicious it is Oepikina minnesotensis.

 

 

16. A possible pedicle valve of Pionodema subequata. 2 cm by 2 cm

16. 

 

 

17. Brachial valve interiors of Sowerbyella curdsvillensis

 

 

 

 

 

18. Inarticulate brachiopods, Lingula. It is difficult to find a pristine one at the site I hunt. But I will keep trying! The name has changed to Pachyglossella eldei.

 

 

 

 

20. Gastropods are infrequently encountered in the Decorah, yet above and below this formation, they are common.

 

 

Edited December 10, 2022 by minnbuckeye

[minnbuckeye]

I continue to have extraneous pictures show up in my posts. They are all Decorah brachiopods and I am too frustrated to get rid of them. So enjoy a few extra pictures without labels.

[Bev]

Great hunt and awesome pics, Mike! That collection so reminded of what I find at the site just east of Mabel on the highway across from the quarry. I can see a bucket of that yielding everything you have here.  :-D And thanks for the extra pics!  :-D

[connorp]

Nice finds Mike. Thanks for sharing.

[PFOOLEY]

Excellent finds, Mike...you could make a field guide with all that diversity.

[Tidgy's Dad]

Really splendid fossils, Mike.  

1. I don't have Platystrophia biforatus (was P biforata, but P. biforatus was first and correct)  listed for the Decorah, mine are all from the Cummingsville Formation. I think that these small winged ones from the Decorah are P. extensa, though larger ones are P. trentonensis. P. amoena is more rounded and doesn't have the wings / ears. 

2. Sowerbyella curdsvillensis, in Iowa, I think. In Minnesota, S. minnesotensis replaces S. curdsvillensis at the very top of the Decorah Shale. The pedicle valve is, as you say, convex and also overlaps the concave brachial valve at the hinge creating a lovely interarea.  

3. It's Sowerbyella curdsvillensis. The one on the right is the concave brachial valve only, so the convex surface we're looking at in the photo is the interior of the valve showing the articulation,muscle attachment ridges etc.

4. Yes, Rhynchotrema wisconsinense. 

5. Very nice Rostricellula colei. 

6. Pretty columnals. You know more than I about crinoids in this formation. 

7. I do like cephalopods. Glad you found a more uncommon one. 

8. Yes, Strophomena filitexta. 

9. I understand that Furcitella scofieldi is mainly found in Minnesota and i don't think this quite fits. I think this is Bellimurina charlottae. 

10. Prasopora insularis perhaps? 

11. This is Hesperorthis tricenaria : 

 

I think yours are Dinorthis pectinella though some of the loose brachial valves could be Hesperorthis. 

 

12. I would say two Lambeophyllum profundum fossilized together.

13. Maybe Stictopora, but I'd need a close-up of the zooecia. There are at least six species of this genus in the Decorah.

14. Really not sure. The top one looks like Pionodema subaequata but the ones at the bottom more like Doleroides parvetus. Can't tell for certain. 

15.Correct. Nice Strophomena septata. 

 And. Oepikina inquassa, I would say. 

16. Could be. Pionodema subaequata is the best I've come up with too. 

17. Brachial valve interiors of Sowerbyella curdsvillensis. 

18. Those are fantastic!  But it's now Pachyglossella elderi and there's a couple of species of Pseudolingula I haven't checked out yet...........

20. You know your snails better than I...............

 

In your extra pictures, the three white ones fourth from bottom of the thread do look like Hesperorthis tricenaria. 

 

Hope this helps.

Fantastic finds,Mike. 

Thanks for sharing.

 

Edited December 11, 2022 by Tidgy's Dad

[oscarinelpiedras]

Awesome finds!! 

[Paleorunner]

Good hunting Mike,    thanks for sharing. 

[FossilNerd]

Not bad at all for the final haul of the season. A lot of great finds there. Thanks for sharing, Mike! 

[minnbuckeye]

@Tidgy's Dad, you didn't mention if you would be in need of any of these fossils. Don't be shy! Your thoughts on my finds are well appreciated as usual. 

 

@Bev, I think the Strophomena from the Mabel site beat none!!!!

[Jeffrey P]

Really nice collection there. Congratulations and thanks for sharing.

[Misha]

Wow! Lovely finds, all the brachiopods are amazing, but I especially like the lingulids, they've always had a special place in my heart

[Tidgy's Dad]

On 12/10/2022 at 6:39 PM, minnbuckeye said:

@Tidgy's Dad, you didn't mention if you would be in need of any of these fossils. Don't be shy! Your thoughts on my finds are well appreciated as usual. 

Thank you. 

Honestly just happy to help. 

You do find some lovely fossils.

 

On the other hand, I'm incredibly greedy.................................................

[minnbuckeye]

@Tidgy's Dad, you mention a Bellamurina valve in your message. I do not see it in my specimens. 

 

 By the way,  Go Morocco!

[Tidgy's Dad]

These ones : 

For me they are closer to Bellamurina : 

than they are to Furcitella, but you may well be right as your specimens don't show the pseudopunctae bumps inside the valves which are often present and Furcitella is smoother inside but doesn't have the same wriggly muscle attachment points that your specimen shows. Also, I can't find a listing for Furcitella in Iowa for this formation or equivalent, but Bellamurina occurs quite commonly it seems. 

[Tidgy's Dad]

1 hour ago, minnbuckeye said:

!

Morocco have played some incredible football. 

The people here are in joy and disbelief. 

The noise and partying are incredible! 

[minnbuckeye]

@Tidgy's Dad, watched the game. Morocco played France very tough. You should be proud! As should the forum members from France. Two outstanding teams!

Edited December 14, 2022 by minnbuckeye

[Tidgy's Dad]

1 hour ago, minnbuckeye said:

@Tidgy's Dad, watched the game. Morocco played France very tough. You should be proud!

I am. 

Tidgy, wifey and I enjoyed it, but the tiredness and injuries had finally caught up with our team. 

The people here are very flat, our neighbours are quite upset. 

Next time! 

[Coco]

 

If Tidgy had played with them, she would have benefited them.

 

coco

Edited December 14, 2022 by Coco

[Tidgy's Dad]

1 hour ago, Coco said:

 

If Tidgy had played with them, she would have benefited them.

 

coco

Congratulations to France, the best team won on the day, experience told. 

But I'm not sure about the England match........................

[Bev]

On 12/10/2022 at 12:39 PM, minnbuckeye said:

@Tidgy's Dad, you didn't mention if you would be in need of any of these fossils. Don't be shy! Your thoughts on my finds are well appreciated as usual. 

 

@Bev, I think the Strophomena from the Mabel site beat none!!!!

@minnbuckeye I AGREE! That is a nice one!  :-D

[Shellseeker]

Those last of the season hunts can produce spectacular finds,  Mike and in your case very spectacular.  It was chilly maybe 50s as I dropped from the Kayak into the morning mist of the Peace River yesterday. The 5 mm wetsuit was barely sufficient for my 1st trip of the season. Congrats on what must be a great memory.   Jack

[minnbuckeye]

Thanks @Shellseeker.

 

16 hours ago, Shellseeker said:

The 5 mm wetsuit was barely sufficient

So I could still wear shorts!!! Unfortunately we will not be visiting Florida this year. My son left Florida for a great job offer in Washington DC involving disaster resiliency around the 18 acres that surround the Capitol Building. It has been very interesting so far! So a visit to DC is in order. And we are also traveling to Animas, New Mexico with my daughter. It is a unique place having an array of large telescopes that they allow visitors to use. We are hoping for clear skies on the 4 nights we have reserved. Hopefully a trip report with Astro photographs and a few rock finds will happen upon return!!!! 

  

 See ya hopefully next year,

 Mike

[Tidgy's Dad]

On 12/10/2022 at 1:04 AM, minnbuckeye said:

Endoceras are the most common cephalopod I encounter in this formation, so the Isorthoceras was a welcome find.

Hi, Mike, I have just been enjoying the lovely chunk of Endoceras proteiforme that you sent me and have been looking at the other nautiloids found in the Decorah.

I think that the species of Isorthoceras that you have here is not I. sociale, which can be found in abundance in Graf, Iowa and elsewhere, but Isorthoceras junceum.

Nice find.