Ichnofossils: burrows, root cast, or something else?

[Darbi]

I found these that resembles burrow or root cast in Ellsworth county, Kansas, USA from my previous trip. The formation these came from are most likely Kiowa formation/Kiowa Shale and the age is Albian. Here's the link to my previous trip. I'm just catching up with the prepping and sorting my fossils from my previous trips.

I am wondering if it is some sort of ichnofossils. Is it burrow, root cast, or something else? Also, is it possible for it to be from geological origin rather than a true ichnofossil?

This one is the largest I found. The center is poorly cemented sandstone and can be easily brushed off with a toothbrush while the outside layer is hard. Notice the winkles around the interior bend. The measurement is in inches (I know I need to get a metric system badly, my apologies!)

 

 

[Darbi]

Similar to the first one...

[Darbi]

The next two resemble a lot like fulgurite, known as 'petrified lightning.' I found both in the beach, but I doubt it is fulgurite because I don't recognize any fused sand grains caused by high temperature and also it's not hollow. Although there's a few large sand grains cemented on these tubes.

[Rockwood]

I think they are essentially ironstone drain 'pipes'. 

[Darbi]

This last one is perhaps the most peculiar. It reminds me a lot about fecal pellet-lined burrow from prehistoric crustacean or Ophiomorpha. At the end of this 'burrow' is a cast of Turritella sp.. Perhaps the shell got trapped in this burrow before it fossilized? I am not aware of any existence of Ophiomorpha and this is the first time I found it from that formation. I hope someone on here will recognize it!

 

[Darbi]

5 hours ago, Rockwood said:

I think they are essentially ironstone drain 'pipes'. 

I think you're right! When you pointed to ironstone drain pipes, I searched through the internet for more information and found a couple topics here on TFF about the same thing. Link and another link. It totally makes sense because I have seen abundant of spherical ironstone concretions at the location I found these. Thank you!

Do you think it's possible it was formed around the trace of tree or plant root? The winkles on the largest (the first picture) made me think of tree root where it bends.

What about the last picture?

[Tidgy's Dad]

Interesting.

That last one looks like pyrite which has formed over something organic, maybe an orthoconic nautiloid, which has then eroded away leaving a hollow space and external impression inside the pyrite. 

Maybe. 

[Rockwood]

2 hours ago, Darbi said:

Do you think it's possible it was formed around the trace of tree or plant root?

I think it may have been @Plax that posted some photos of wood in ironstone from his collection one time. It does happen.

[Ruger9a]

Sorry I can't help with the identifications, but they are all interesting finds.

[erose]

The last one is a classic Ophiomorpha burrow. Those are attributed to crustaceans building burrows in a sediment that required them to fortify the walls with little mud balls (NOT fecal pellets) The gastropod inside is just serendipity. The others all look like the big burrows we find in the Cretaceous limestones of Texas.  They could have been made by anything from clams to worms to heart urchins. The burrow fills back in and the density of the matrix is different enough that they become preserved. Looks like the infill was slightly more iron-rich.

[Darbi]

16 hours ago, Tidgy's Dad said:

Interesting.

That last one looks like pyrite which has formed over something organic, maybe an orthoconic nautiloid, which has then eroded away leaving a hollow space and external impression inside the pyrite. 

Maybe. 

Pyrite/marcasite makes sense because it smells like gun powder and it is abundant at where I found it. As for the external impression, I doubt it's an orthoconic nautiloid, I am not aware of any orthonconic nautiloid fossils from Kiowa formation. The impression is exactly the same as Turritella sp. found in the area and it is extremely abundant. The chance is that it's probably from Turritella sp. , but thank you for your suggestion!

 

13 hours ago, Rockwood said:

I think it may have been @Plax that posted some photos of wood in ironstone from his collection one time. It does happen.

Thank you for your input!

 

9 hours ago, Ruger9a said:

Sorry I can't help with the identifications, but they are all interesting finds.

That's alright, thank you though!

 

5 hours ago, erose said:

The last one is a classic Ophiomorpha burrow. Those are attributed to crustaceans building burrows in a sediment that required them to fortify the walls with little mud balls (NOT fecal pellets) The gastropod inside is just serendipity. The others all look like the big burrows we find in the Cretaceous limestones of Texas.  They could have been made by anything from clams to worms to heart urchins. The burrow fills back in and the density of the matrix is different enough that they become preserved. Looks like the infill was slightly more iron-rich.

That's fascinating, thank you! The environment the Kiowa formation developed in was mostly brackish, river delta, and salt water marsh ecosystem, according to several paleontology literature I read. I found the reed fossils in the same trip and flora fossils are known to be found there too. Paleontologists have found tree casts and amber there too in the same area from the same formation. I'm just adding it might not be just an animal burrow.

How do you tell the difference between mud balls-lined burrow and fecal pellets-lined burrow?

 

[Tidgy's Dad]

Just now, Darbi said:

Pyrite/marcasite makes sense because it smells like gun powder and it is abundant at where I found it. As for the external impression, I doubt it's an orthoconic nautiloid, I am not aware of any orthonconic nautiloid fossils from Kiowa formation. The impression is exactly the same as Turritella sp. found in the area and it is extremely abundant. The chance is that it's probably from Turritella sp. , but thank you for your suggestion!

I'm afraid I rather had a bit of a stupid attack regarding the orthocone comment. 

Forgot or hadn't read the post properly. 

[Darbi]

4 minutes ago, Tidgy's Dad said:

I'm afraid I rather had a bit of a stupid attack regarding the orthocone comment. 

Forgot or hadn't read the post properly. 

That's alright. I completely understand because I am mildly dyslexic. If I'm not careful, I tend to misread or mispronounce the words.

[erose]

16 minutes ago, Darbi said:

How do you tell the difference between mud balls-lined burrow and fecal pellets-lined burrow?

 

Do a web* search. Fecal pellets are, as far as I know, much smaller (<mm dia) and cylindrical in shape. You ever see crayfish turrets along a muddy creek? The balls are round like balls and bigger (2-4mms dia). There are fossil burrows full of fecal pellets but they are different. 
 

*but look at a bunch of images. There are a few mislabeled ones out there.

[Darbi]

7 hours ago, erose said:

Do a web* search. Fecal pellets are, as far as I know, much smaller (<mm dia) and cylindrical in shape. You ever see crayfish turrets along a muddy creek? The balls are round like balls and bigger (2-4mms dia). There are fossil burrows full of fecal pellets but they are different. 
 

*but look at a bunch of images. There are a few mislabeled ones out there.

I wish the answers will be more straightforward when I do a web search. A lot of paleontology websites and literature are not clear on how to differ the mud balls-lined burrow from fecal pellets-lined burrow, they seem to imply that the fecal pellets can be spherical. For example: KU Ichnology on Ophiomorpha --- "Trace is the dwelling burrows of decapod crustaceans, including numerous species of Thalassinidean shrimp. Tube margins are lined with fecal pellets." There's also pictures on this KU Ichnology website that shows the fossil burrows with spherical pellets.

Again, thank you for help.

[Rockwood]

42 minutes ago, Darbi said:

I wish the answers will be more straightforward when I do a web search. A lot of paleontology websites and literature are not clear on how to differ the mud balls-lined burrow from fecal pellets-lined burrow, they seem to imply that the fecal pellets can be spherical. For example: KU Ichnology on Ophiomorpha --- "Trace is the dwelling burrows of decapod crustaceans, including numerous species of Thalassinidean shrimp. Tube margins are lined with fecal pellets." There's also pictures on this KU Ichnology website that shows the fossil burrows with spherical pellets.

Again, thank you for help.

I've never seen the actual study results, but I believe the strongest evidence against the common perception that ghost shrimp use fecal matter to line their burrows comes from observations of modern communities.