How do I tell if it's a fossil or just a fun shaped rock??

[KelseyM]

This may be a silly question, but how do I know if something is actually a fossil or just a weird shaped rock? Also, if anyone knows - how do these weird shaped rocks form in the slate/shale if they aren't fossils? Not looking for an ID (yet!), just trying to figure out how all the weirdly shaped rocks came to be!

I went hiking with my mom in our backyard because she found what we believe to be nautiloid fragments (link to ID thread) and we wanted to see if we could get more. Well we found lots of oddly shaped rocks, but are unsure if they are actually anything. If it helps, we are in a creek in Groveland, Livingston County, New York. A geologist friend said that creek bed looks like shale slate.

The only thing we pulled out that I have pictures of right now is a long wormy looking one. One picture of it in the rock and three after we got it out. I haven't been able to take any pictures with size reference sorry  I don't have it with me right now, but from memory I'd estimate it's at least ~12-15 cm (5-6 inches).

 

Thanks!

[KelseyM]

Pictures of the creek where we pulled them out

[Kane]

Neat worm burrows. These are burrows that get filled with sediment.

 

in terms of your question, it’s not a hard and fast rule, but many fossilized organisms have some kind of symmetry. Bicameral symmetry is fairly common, but other fossils like crinoids and echinoderms can have multi-fold symmetry. Sometimes the symmetry is along a different plane (such as for bivalves and ammonoids). 

 

Just pick up anything interesting and post it here!  

[sharkdoctor]

Thanks for providing my favorite phrase of the week: "fun shaped rocks"!

Fossils are DEFINITELY fun-shaped rocks :-)

[digit]

24 minutes ago, Kane said:

Just pick up anything interesting and post it here!  

Yup. That's a tried and true method of distinguishing fossils from the fakers that Mother Nature plants to keep us all on our toes. Even items that are not fossils (or trace fossils like worm burrows) can be interesting enough to be picked up and find their way into a display case or a desk.

 

A belated welcome to the forum!

 

 

 

Cheers.

 

-Ken

[FranzBernhard]

On 7/8/2019 at 12:02 PM, KelseyM said:

Pictures of the creek where we pulled them out

 

Nice place and nice rocks to hunt!!! Congrats to having something like this in your backyard!

 

On 7/8/2019 at 12:00 PM, KelseyM said:

Groveland, Livingston County, New York

Maybe @Al Tahan is able to pinpoint in which formation you are and what you can expect fossil-wise!
Franz Bernhard

[KelseyM]

Thanks everyone!! I will get some more pictures of our other finds and post them on the ID forum later today or tomorrow  Regardless of what everything is, it's all being put on display in my cubicle by the end of this week!

[Mediospirifer]

I don't know how much topographical variation there is in Livingston Cty. That said, I do know that there are some good exposures of Windom shale (Middle Devonian, Moscow Formation) in some creek beds.

 

Trilobites (particularly Eldredgeops, Greenops, and Dipleura), brachiopods (quite a variety!), bryozoans (both free and encrusting forms), crinoid bits, and horn corals are what I've found most commonly, with an occasional ammonoid, bivalve, gastropod, blastoid (ok, I've only ever found one), or fish material (again, I've only found one).

 

Do you have a fossil ID reference book? I recommend this one: Field Guide to the Devonian Fossils of New York by Karl Wilson.

 

Enjoy the hunting!

 

[KelseyM]

2 minutes ago, Mediospirifer said:

I don't know how much topographical variation there is in Livingston Cty. That said, I do know that there are some good exposures of Windom shale (Middle Devonian, Moscow Formation) in some creek beds.

 

Trilobites (particularly Eldredgeops, Greenops, and Dipleura), brachiopods (quite a variety!), bryozoans (both free and encrusting forms), crinoid bits, and horn corals are what I've found most commonly, with an occasional ammonoid, blastoid (ok, I've only ever found one), or fish material (again, I've only found one).

 

Do you have a fossil ID reference book? I recommend this one: Field Guide to the Devonian Fossils of New York by Karl Wilson.

 

Enjoy the hunting!

 

Thanks! I'm definitely going to have to get one!

[Mark Kmiecik]

3 hours ago, KelseyM said:

This may be a silly question, but how do I know if something is actually a fossil or just a weird shaped rock? Also, if anyone knows - how do these weird shaped rocks form in the slate/shale if they aren't fossils? Not looking for an ID (yet!), just trying to figure out how all the weirdly shaped rocks came to be!

First, welcome to the forum from Illinois.

 

To answer your question -- It takes a lot of experience and a lot of reading/research. Expose yourself to as much of this forum and any books as possible. Even the most knowledgeable members of this forum, and many have doctorates in the sciences, don't know everything there is to know about geology and fossils and never will. There is just too much information for one person to accumulate in one lifetime and the database is expanding at a high rate with each new day. With time you will get to know the basics quite well by simply being exposed to them and seeing numerous specimens of the same species in differing preservation states from around the world. If you're having fun collecting the knowledge will come easily and without tedium. In the meantime post photos of what you need identified in the ID section of the forum. 

 

P.S. -- Just to give you an idea of how difficult identification can be, there are more than 20,000 recognized species, and that's only species of trilobites. Then there's everything else. Insects, molluscs, fish, reptiles, mammals, corals, arthropods, etc. That's why so many professionals specialize.

[KelseyM]

Just wanted to update that I was able to measure and it is just over 8 inches long! I was worried that my estimate would be an overestimate but I guess I was understating the size a bit. I just posted a few of the other things we found in the ID forum  Thank you to everyone! I really appreciate all the info!!

[siteseer]

On 7/8/2019 at 1:06 PM, Mark Kmiecik said:

First, welcome to the forum from Illinois.

 

To answer your question -- It takes a lot of experience and a lot of reading/research. Expose yourself to as much of this forum and any books as possible. Even the most knowledgeable members of this forum, and many have doctorates in the sciences, don't know everything there is to know about geology and fossils and never will. There is just too much information for one person to accumulate in one lifetime and the database is expanding at a high rate with each new day. With time you will get to know the basics quite well by simply being exposed to them and seeing numerous specimens of the same species in differing preservation states from around the world. If you're having fun collecting the knowledge will come easily and without tedium. In the meantime post photos of what you need identified in the ID section of the forum. 

 

P.S. -- Just to give you an idea of how difficult identification can be, there are more than 20,000 recognized species, and that's only species of trilobites. Then there's everything else. Insects, molluscs, fish, reptiles, mammals, corals, arthropods, etc. That's why so many professionals specialize.

 

I've been collecting fossils for over 30 years.  It's all about knowing shapes and sizes, types of preservation, what's possible and leaving room for the apparently impossible.  I see things at shows I don't see in books and vice versa.  It's great looking at someone else's collection and books.  It's a lot of fun to go to a museum.  Over time, you recognize misidentifications and inaccuracies in your own writing and others.

 

I'm still going to try to know everything.  

 

Jess