I found a fossil bed and I have a ton of questions.

[allquieton]

I’m pretty new to fossils—I have found a few strays before. But the other day, I found what appears to be an entire fossil bed. It’s about a 150 square foot area, full of fossils, on a hillside ridge near the Whetstone Mountains, outside of Tucson, AZ.
 

I don’t know if this sort of find is very common. But there is a layer with what I think are marine fossils—hundreds and hundreds of seashells. And then about 50 feet in elevation above that layer are what appears to be long bone fossils. Dozens and dozens of them. Most are about as thick as my fingers and the longest are about 18 inches.
 

The reason I think they are bones is because of Photos #9-12, which show what seems to be a bone which was snapped in half before fossilization. Please correct me if I’m wrong—I am no expert here.
 

I believe there are still some seashell fossils mixed in with the bones. But there are no bones in the lower seashell layer that I could tell.
 

The Carmex container is 35mm in diameter.
 

Most of the well-preserved seashells are 1cm long or less. The shells that appear to be sitting on top of the bedrock are actually firmly attached.

There are also loose bone fossils that have washed out of the rock—see photo 19.
 

I’m sorry my photography is not very good. I do have several more photos if anyone wants to see them. Some of the photos rotated when uploaded--I'm not sure why.
 

I am very curious to know if anyone can tell me what kind of bones these might be. (If they are bones.) And how old they might be.

I’m also curious to know if anyone can age and identify the kinds of sea life in the lower fossils. Photo #5 has a bigger spiral that looks like a fossil.
 

Also can anyone tell me what kind of stone is the gray rock which the fossils are trapped in? It’s very gritty and there’s absolutely tons of it. Is the gray rock what you would call bedrock? Also, what kind of stone are the fossils themselves in this case?
 

Really I would be grateful to know anything you all could tell me about these fossils. I’m absolutely fascinated by it all.

Thanks in advance.

 

 

[jpc]

Those are some beatiful little brachiopods.  It looks like they are in  limestone.

 

I don't think your 'bones' are actually bones.  Photos 17 & 18 shows the texture very well, and it is not a bone texture.

[Tidgy's Dad]

Yes, rhynchonellid brachiopods. Lovely. 

[Top Trilo]

Those are some really cool brachiopods and gastropod (the spiral)! I can't answer your questions but nice find!

[val horn]

The brachiopods are really nice and suggest a paleozoic time frame.  I am not sure about the red brown items.  I am no expert but I could convince myself that the semiciruclar piece in fig 12 could be a centrum from a permian tetrapod.  I have only collected permian fossils in waikura oklahoma once but  some of what I found resembles his finds.  To my eyes the permian bone had a very odd texture without a clear distinction of cortex and trabecular bone even on pieces I was reasonably sure of.  i am showing what i thought was a centrum,both sides of piece of jaw bone and the  end of a long bone ( each ~1cm)).    I think that it would be a good idea to check a detailed geological map to get a clearer  handle on the time, and taking one or two pieces into a museum or university.

[allquieton]

JPC, Tidgy's Dad, Top Trilo, and Val--thanks you so much for the information. I've been googling brachiopods and rhynchonellid brachiopods and it's all so richly interesting. Val, a special thanks for some ideas and possibilities, and for the photos to compare. It definitely makes me want to research it all some more. I will try to make it back to the site and look around some more--I hardly had any time when I was there. 

 

Thanks again, all of you, and let me know if you think of anything else!

 

[Sjfriend]

The brachiopods are a great find. And yes, you can often find mass amounts of shells in one area. The water currents will pile them up before they get buried.

 

As for the red things, my guess is flint infill. They can be very common in different rock beds. I've seen a lot of them in the Huachuca and Chiricahua Mountains 

[Sjfriend]

And I would love to find that shell bed! Never hiked the Whetstones

[Thames Adventurer]

Could the red things be the trace fossil & leftover infill remains of marine animal burrows? 

There's a whole bunch of marine critters which make burrows in the substrate, from crabs to snails, lobsters, worms and more.