Possible Trace Fossil

[Andúril Flame of the West]

Hello all, 

 

A few months back I happened upon an intriguing rock while taking a walk in the woods. The main groove on the front of the rock struck me as a possible trace fossil (perhaps a worm burrow or a tunnel created by plant roots). I considered the possibility that it could potentially be a fossil since it was found in the Newark Supergroup of northern Virginia which is know to have some fossiliferous rocks. However, I fully expect that it is simply an artifact of weathering or that it has a geologic origin. Can any confirm whether it is a trace fossil or simply a case of weathering?

 

I’ll tag a few members that I feel are knowledgeable on this subject: @Fossildude19  @EMP @cck @WhodamanHD

 

I deeply appreciate all input. 

 

[debivort]

I'd lean yes, trace fossil

[cck]

Given the location and formation, it’s certainly possible.. I’d only caution that scars from modern farm implements can be very compelling decoys in this red mudstone… 

[Andúril Flame of the West]

Appreciate the replies. It was my honest opinion that this was simply a result of weathering that happened to catch my eye. That being said, I agree that heavy machinery/farm implements could also make such a marking. It is possible that the place where it was found was once farmland, though I do have some doubts since it was found on a very steep slope along a dirt trail in the woods. I am not sure whether this would detract from the possibility of it being a trace fossil, but it was found as it is shown in the pictures buried in mud with some similar rocks nearby. 
 

If it is indeed a trace fossil, has anyone seen anything similar in Newark Supergroup red beds? And are there any diagnostic features of the specimen that make it appear more like a trace fossil than an artifact of weathering? Again, I deeply appreciate all the feedback that you provide. 

[EMP]

I'd lean towards it being a trace fossil, too. 

[Miocene_Mason]

If it is a trace fossil, its not a surface one because usually the mid atlantic newark surface traces tend to have a glossy sheen on them in my limited experience. It could be a burrow.

[EMP]

4 hours ago, WhodamanHD said:

If it is a trace fossil, its not a surface one because usually the mid atlantic newark surface traces tend to have a glossy sheen on them in my limited experience. It could be a burrow.

 

The thing that sticks out to me is the small ridge in the middle of the impression. That doesn't seem like something I've found in "normal" worm burrows, especially from the Newark Group. It almost looks similar to tail-drag/imprint traces from lizards or amphibians:

 

 

Like the photo on the top left, where there's a small ridge in the middle of the tail's imprint.

 

I'm not saying it is such a trace fossil, but it does seem unlike most burrows I've found in the Newark. Maybe a worm or insect could have produced the ridge. 

[Andúril Flame of the West]

Thanks for weighing in @WhodamanHD! As I have mentioned before, I did not at all expect this to be a trace fossil and I was surprised when other members felt that it could be one. I believe I know what you are referring to though as I have seen some examples online of smaller Newark trace fossils with a glossy sheen. 

[westcoast]

Also worth noting that as it is a loose clast you don't have any evidence to say if that is an upper or lower surface, so the median ridge could be an impression of a furrow. Flip the rock over and picture that.

In any event, I think you would need to find more examples to say if it is a trace fossil or not.

[doushantuo]

the images figured by EMP are from:

 

 

Unique trackway on Permian Karoo shoreline provides evidence of temnospondyl locomotory behaviour
David P. Groenewald ,Ashley Krüger,Michael O. Day,Cameron R. Penn-Clarke,P. John Hancox,Bruce S. Rubidge

https://doi.org/10.1371/journal.pone.0282354

journal_pone.0282354.pdf

suppl.info: https://www.morphosource.org/projects/000494771?locale=en.

 

Swimming trails are attributed to a rhinesuchid temnospondyl

Karoo/Beaufort Group/South Africa/bedding plain ichnoassemblage 

Edited May 12, 2023 by doushantuo

[Andúril Flame of the West]

On 5/11/2023 at 7:30 PM, EMP said:

 

The thing that sticks out to me is the small ridge in the middle of the impression. That doesn't seem like something I've found in "normal" worm burrows, especially from the Newark Group. It almost looks similar to tail-drag/imprint traces from lizards or amphibians:

 

 

Like the photo on the top left, where there's a small ridge in the middle of the tail's imprint.

 

I'm not saying it is such a trace fossil, but it does seem unlike most burrows I've found in the Newark. Maybe a worm or insect could have produced the ridge. 

 

That is quite intriguing and I do agree that the ridge in the specimen resembles the tail drags pictured. I know that swimming traces attributed to Rhynchosauroides have been found in the Newark Supergroup, but are tail drags such as the one in the image also known from Newark sediments? Thanks @doushantuo for posting the link to the paper and providing the additional information. Very informative and interesting article that I plan to read through more thoroughly in the future. 

 

21 hours ago, westcoast said:

Also worth noting that as it is a loose clast you don't have any evidence to say if that is an upper or lower surface, so the median ridge could be an impression of a furrow. Flip the rock over and picture that.

In any event, I think you would need to find more examples to say if it is a trace fossil or not.

 

Upon looking at the specimen again I noticed some intriguing features that could help in confirming whether it is a trace or what kind of trace it could be. I will upload some photographs of the features taken in natural sunlight over the weekend. I appreciate the input regarding gathering more evidence. I plan to return to the area where the specimen was recovered and will document any possible trace fossils or other interesting features. 

 

I suspect that if the specimen is a trace fossil it is not anything incredibly interesting, but would anyone recommend that I contact Dr. Weems or Dr. Paul Olsen to get an expert opinion on what the specimen may be? I've filtered through many papers authored by both and from my understanding they seem to be some of the foremost experts on the Newark Supergroup. As always, I deeply appreciate the suggestions, help, and advice that everyone has so generously given .

[cck]

Yes, those two gentlemen would be the ones to contact… interested to hear their opinions.

[doushantuo]

I would CERTAINLY recommend contacting Elizabeth Gierlowski-Kordesch

[Andúril Flame of the West]

Thanks to everyone for the comments; I have sent e-mails to both Dr. Weems and Dr. Olsen to consult their expertise. I did take a few photographs of some characteristics of the specimen that I found intriguing. Unfortunately I was not able to take them in natural sunlight, but I hope that everyone can still see the features relatively well. 

 

 

At what I would call 'the bottom' of the supposed trace there appear to be features that resemble scratch marks. I am not sure what they are or whether they could indicate something about the specimen. 

 

 

Two views of what I would consider to be the 'top' of the trace. I was intrigued by this second feature adjacent to the main feature in question. Could this be a branching section of a tunnel or could it indicate something else about the specimen?

 

 

The final intriguing feature is this faint marking that was on the back of the specimen. Could this be another trace?

 

9 hours ago, doushantuo said:

I would CERTAINLY recommend contacting Elizabeth Gierlowski-Kordesch

 

I appreciate the suggestion, but after conducting a quick google search it seems that she passed away several years ago. 

 

Again, thanks to everyone for your comments and suggestions. I am beginning to enjoy the journey of identifying this specimen! 

[doushantuo]

"I am beginning to enjoy the journey of identifying this specimen! "

 

 

ditto

[patelinho7]

I’m interested in seeing where this goes, keep us posted on what Dr. Weems and Dr. Olsen say. I had been working with Dr. Weems on some interesting stuff from the Potomac group of MD but recently turned my attention to the culpeper basin as I live in nova and have been trying to nail down some hunting spots closer to home. I may have to reach out to you in the near future if you don’t mind, I have some interesting things I’ve found since talking to and perusing old papers of Dr. Weems that I would love to run by a fellow VA searcher. I agree with EMP and also am intrigued by the “scratches” at one end of the groove, something that definitely points to a possible trace fossil for me.

[Andúril Flame of the West]

On 5/14/2023 at 9:35 PM, patelinho7 said:

I’m interested in seeing where this goes, keep us posted on what Dr. Weems and Dr. Olsen say. I had been working with Dr. Weems on some interesting stuff from the Potomac group of MD but recently turned my attention to the culpeper basin as I live in nova and have been trying to nail down some hunting spots closer to home. I may have to reach out to you in the near future if you don’t mind, I have some interesting things I’ve found since talking to and perusing old papers of Dr. Weems that I would love to run by a fellow VA searcher. I agree with EMP and also am intrigued by the “scratches” at one end of the groove, something that definitely points to a possible trace fossil for me.

 

I'd certainly be interested in having a conversation with a fellow Virginia searcher. Just as a heads up, you may want to adjust your settings if you want to have a conversation through PM (unless there is something wrong on my end). 

[Andúril Flame of the West]

As an update to this post, I have received responses from both Dr. Olsen and Dr. Weems. I want to give a special thanks to @MarcoSr for helping me get into contact with Dr. Weems. The general consensus is that the features of the specimen are not trace fossils, but that they are impressions that were carved into the stone by modern tree roots. This evaluation seems to fit pretty well when considering where the specimen was found and the manner in which it was found. Although it is unfortunate that it did not turn out to be a trace fossil, it was quite an interesting journey here on the forum attempting to identify the specimen and it will certainly make for another unique rock for the garden. Again, I want to thank both experts who gave final evaluations on the specimen and everyone here on the forum who has commented on this thread. 

[debivort]

I guess it's a future trace fossil.