Mish Mash of Burlington Limestone Fossils to ID

[minnbuckeye]

I finally had a chance to organize my fossils from my last excursion to Iowa. The following 5 fossils are new to me and I struck out trying to identify them. Hence the need for some assistance. They are from the Burlington Limestone/ Mississippian of SE Iowa. 

 

 1. This appears to be in the shape of a crinoid cup. It is large and fits Cactocrinus imperator which is suppose to have a smooth surface in the Burlington. 

 

 2. The left side is broke away. Reminds me of a  bellerophon like fossil but can find no mention. 

 

  3. There are lots of shark teeth in the upper Burlington. But this looks more bone like. Your thoughts??

 

 4. This brachiopod is long and skinny and has been broken off on the left side. Most species listed are broader than long, so this one has me confused.

 

 

 5. I believe this is a brachiopod but who knows!! Flat as a pancake. Can't find an image remotely close to this so maybe crinoidal??

 

Thanks for any insight. 

 

Edited July 25, 2021 by minnbuckeye

[minnbuckeye]

@Jackson g, I believe you hunt the Burlington. Anything look recognizable? @Tidgy's Dad Adam, any thoughts on the brachiopods?

[Tidgy's Dad]

Hi, Mike: 

Interesting finds. 

I think the first 'brachiopod' is actually a bivalve, though I may well be wrong. I understand they're quite uncommon in the Burlington.

The last photo is a brachiopod, but I'm sorry to say I have no idea which one. There's at least a hundred and ten species in the formation and I haven't studied them yet. 

Not much help, I'm afraid.  

[minnbuckeye]

@Tidgy's Dad, Thanks for looking. It always seems the formations I hunt have had minimal research done. Though these are not exceptional fossils, I like to keep one of everything,no matter how insignificant and try and ID. Maybe one day the answer will show up! By the way, the shell in picture #4 has two fractures in it. One from the tip down to the 5 cm mark and a second fracture from the 5 cm mark going up and right. This gives the definite look of a bivalve vs brachiopod.

[DPS Ammonite]

For number 2 , consider a platyceratid

 

https://en.m.wikipedia.org/wiki/Platyceratidae

 

https://en.m.wikipedia.org/wiki/Platyceras

 

 

[Rockwood]

While you're at it, this would go nicely with the crinoid cup idea. These little bivalves gastropods were thought to be coprophages which specialized in crinoid waste.

Ya, I know, it's gross, kids, but it happens.

 

Edit: gastropod, not bivalve

[minnbuckeye]

@DPS Ammonite, Thank You So Much! The ID is spot on and goes 100% with Burlington matrix being 99% crinoidal. Platyceratids had a smorgasboard to feed on!