Dinosaur Footprint?

[EMP]

I found this specimen while hunting in the vicinity of Washington DC. I know dinosaur footprints have been found from the formation I was hunting in (Patuxent Formation, Potomac Group), including some fairly recently. I have found numerous fossils from the area I recovered this from, however those were from the ironstone/mudstone and not this kind of rock. I believe it might be a weathered dinosaur footprint, perhaps hadrosaur? From what I've read ornithopod, hadrosaur, sauropod, and ankylosaur tracks are fairly common in the Patuxent. It does take on the appearance of a fragmentary hadrosaur footprint I've seen online: 

 

https://www.pinterest.com/pin/152278031125460468/

 

 

The age of this fossil is lower Cretaceous, about 120 million years old. 

Patuxent Formation, Potomac Group. 

 

Thanks for any help! 

 

 

 

 

[Troodon]

Footprints have been found in that area see attached paper on it.  Unfortunately I don't see anything that jumps out that says your plate is one.  

 

http://www.ecphora.net/mgs/articles/Patuxent dinosaur footprints.pdf

[Fossildude19]

I'm not seeing any footprints here, unfortunately.  

 

[jpc]

I see no footprint either....  Sorry to say.  

[Kane]

Ditto.  If it is one, then it might be of some utility to uncover whatever else might be on that layer to find trackways. A potential footprint in isolation is not as convincing as locating others of its kind in the same sediment layer.

[JarrodB]

Sorry but I"m not seeing it. 

[EMP]

1 hour ago, Kane said:

Ditto.  If it is one, then it might be of some utility to uncover whatever else might be on that layer to find trackways. A potential footprint in isolation is not as convincing as locating others of its kind in the same sediment layer.

 

Okay. 

 

1 hour ago, Troodon said:

Footprints have been found in that area see attached paper on it.  Unfortunately I don't see anything that jumps out that says your plate is one.  

 

http://www.ecphora.net/mgs/articles/Patuxent dinosaur footprints.pdf

 

To me it kind of looked similar to the specimen on page 9 of that report. 

 

1 hour ago, jpc said:

I see no footprint either....  Sorry to say.  

 

16 minutes ago, JarrodB said:

Sorry but I"m not seeing it. 

 

I hate to ask, but what makes you say no as opposed to yes? Is there some structure that's missing that I don't see? I'd like to learn so I can ID stuff on my own eventually. 

[JarrodB]

5 minutes ago, EMP said:

 

Okay. 

 

 

 

 

I hate to ask, but what makes you say no as opposed to yes? Is there some structure that's missing that I don't see? I'd like to learn so I can ID stuff on my own eventually. 

I collect tracks and have multiple tracks for sale in the fossil sale section. Yours looks natural. Some of the other guys who replied are dinosaur experts and can explain better. 

[Troodon]

 I just do not see a print, shape that was formed by a foot,  looks just like a naturally geologic occurence.  I also dont see a match to the ones in the paper. 

[EMP]

2 minutes ago, Troodon said:

 I just do not see a print, shape that was formed by a foot,  looks just like a naturally geologic occurence.  I also dont see a match to the ones in the paper. 

 

But why does it look just like weathering and not a footprint? Is there some special way to tell? I'd like to eventually see on my own if something's differential weathering or not. 

[Troodon]

13 minutes ago, EMP said:

 

But why does it look just like weathering and not a footprint? Is there some special way to tell? I'd like to eventually see on my own if something's differential weathering or not. 

Where is the shape of the negative of a foot?  Yours has no defined shape its natural. You need to be able to see digits, possibly pads like the one in the picture.  Search online and try to use those images to compare against. 

[abyssunder]

I think, there is nothing more than differential weathering of a sedimentary structure.

[JohnJ]

The partial 'track' shape in your rock is created by the eroded surface of a missing part of the top layer of rock...rather than an impression in the contiguous surface layer.

[EMP]

12 minutes ago, Troodon said:

Where is the shape of the negative of a foot?  Yours has no defined shape its natural. You need to be able to see digits, possibly pads like the one in the picture.  Search online and try to use those images to compare against. 

 

Thanks for making it a little clearer. However, I still don't know how to tell if it's the negative shape of a foot or not? To me it looks like my thing does have the "pad" and "digit", particularly in the third picture. 

[Auspex]

13 minutes ago, JohnJ said:

The partial 'track' shape in your rock is created by the eroded surface of a missing part of the top layer of rock...rather than an impression in the contiguous surface layer.

"Post Pedum" as it were...

The feature breaches several sedimentary layers, and not by displacing them.

[jpc]

I am a footprint skeptic from the start.  If it is not glaringly obvious, I need to see a few footprints on a flat surface of rock. 

One of the things I see here is the top surface has a different color than the "footprint".  Also different texture.  It is as if the top layer has been eroded away.  In the case of a footprint, the top layer would be pushed into the muck (now rock) and it would look like one surface. I also see no  obvious toe impressions, be they theropod or not.  

[Miocene_Mason]

I don’t see this one either unfortunately, looks unlike the other ones I’ve seen from the area. 

[EMP]

5 minutes ago, jpc said:

I am a footprint skeptic from the start.  If it is not glaringly obvious, I need to see a few footprints on a flat surface of rock. 

One of the things I see here is the top surface has a different color than the "footprint".  Also different texture.  It is as if the top layer has been eroded away.  In the case of a footprint, the top layer would be pushed into the muck (now rock) and it would look like one surface. I also see no  obvious toe impressions, be they theropod or not.  

 

How does one tell a toe imprint from a normal hole? Lots of my rocks have strange imprints in them, and I've left many behind because I don't want to carry plain rocks back. Is there a good way to tell in the field so I don't waste my effort on ordinary stones?

[Bobby Rico]

I have a couple of footprints but sorry I can’t see what your are seeing here. 

 

[EMP]

12 minutes ago, jpc said:

I am a footprint skeptic from the start.  If it is not glaringly obvious, I need to see a few footprints on a flat surface of rock. 

One of the things I see here is the top surface has a different color than the "footprint".  Also different texture.  It is as if the top layer has been eroded away.  In the case of a footprint, the top layer would be pushed into the muck (now rock) and it would look like one surface. I also see no  obvious toe impressions, be they theropod or not.  

 

3 minutes ago, Bobby Rico said:

I have a couple of footprints but sorry I can’t see what your are seeing here. I hope you don’t mind   but I highlighted the area I think you meant. To help with the ID ( if you are not happy for me to do that I will delete no problem)

 

No, the "footprint" is the one big impression. 

 

That might be a problem later on, because almost every single specimen from these deposits is just one or maybe two prints on a single piece of rock. 

 

I think for simplicity I'll post the other possible ones on here later, after I get a better idea on how to tell so as not to waste everyone's time. I appreciate the comments, my goal is to eventually be able to discern in the field what's a footprint and what's not because I've seen stuff online but out in the field nothing ever looks exactly the same. 

[Bobby Rico]

@EMP sorry I was not much help. It is better to take things home and debate it on TFF than to leave it in the field. Looking forward to see the rest. 

 

I brought one home last year but it was just a suggestive shape.

 

Bobby

[EMP]

15 minutes ago, Bobby Rico said:

@EMP sorry I was not much help. It is better to take things home and debate it on TFF than to leave it in the field. Looking forward to see the rest. 

 

I brought one home last year but it was just a suggestive shape.

 

Bobby

 

Probably nothing like the first one. 

 

The top one looks like it has multiple potential ones. 

 

 

[ynot]

When looking at a print, there will be an area where the foot pushed the mud away as it was put into the mud. This causes a ridge or lifted area around the print. There will also be an area of distortion inside the print where pressure was used to "push off" for the next step. There should be evidence of the toes and foot pad. These features can vary depending on how wet the mud was when the animal walked across it.

The surface of the rock should have a continuous continuity of structure. 

 

Your rock does not have any of these features. It shows abrupt fracture features that have a vague shape, but no continuity.

[JohnJ]

2 hours ago, EMP said:

 

How does one tell a toe imprint from a normal hole? Lots of my rocks have strange imprints in them, and I've left many behind because I don't want to carry plain rocks back. Is there a good way to tell in the field so I don't waste my effort on ordinary stones?

At least six different members have tried to explain the difference between your rock an real track characteristics.  Hopefully, this will help you see what to look for.

 

[EMP]

35 minutes ago, ynot said:

When looking at a print, there will be an area where the foot pushed the mud away as it was put into the mud. This causes a ridge or lifted area around the print. There will also be an area of distortion inside the print where pressure was used to "push off" for the next step. There should be evidence of the toes and foot pad. These features can vary depending on how wet the mud was when the animal walked across it.

The surface of the rock should have a continuous continuity of structure. 

 

Your rock does not have any of these features. It shows abrupt fracture features that have a vague shape, but no continuity.

 

What about the other ones I posted? The top one has the same kind of rock at the bottom of the print, it shows (what looks like to me) a "pad" and "digits", and some possible distortion. 

17 minutes ago, JohnJ said:

At least six different members have tried to explain the difference between your rock an real track characteristics.  Hopefully, this will help you see what to look for.

 

 

That was referring to toe imprints. Everyone seems to be only talking about footprints.