Brachiopod and Ammonite?

[Sagebrush Steve]

I know this is a long shot, but I was hoping someone could identify these two fossils I know almost nothing about.  Back in the 1970s and 1980s, my mother owned a lapidary and rock shop in Southern California.  Her customers would sometimes give her samples of rocks and fossils they had dug.  I believe that is how she got these.  When she retired she packed everything up and moved it to her home.  I inherited some of it when she passed away.  That’s about all I know of them.  The brachiopod looks like it might be a Mucrospirifer sp., but I really don’t have any idea about the ammonite.  Perhaps something from the Goniatiida order?

                                                    

I know some of you will want to know the rock formations they came from.  I’m not a geologist so I don’t really know.  I can only tell you I found them in the Cardboard Box member of the Spare Bedroom formation, within the Old House group.  (I thought I might apply to register those names with the USGS Geologic Names Committee).

[Ramon]

I agree the first one is a brachiopod, and the second one is an Ammonite. I just don't know the name scientific name of them.

 

Nice Ammonite, by the way!!! 

[abyssunder]

Try to make a high-res picture to let the suture lines more visible.

 

Figure 6. Types of suture lines.

[Fossildude19]

You are correct.

Your brachiopod looks like a Mucrospirifer  sp.,   possibly M. mucronatus. 
Devonian in age. 

[Ludwigia]

I'll go along with abyssunder. In order to attempt to identify the "ammonite", we'd need close ups, also of the mouth aperture and venter.

[Darktooth]

A couple nice "Box"finds!

[Sagebrush Steve]

2 hours ago, abyssunder said:

Try to make a high-res picture to let the suture lines more visible.

 

Figure 6. Types of suture lines.

OK, I was going to say that I couldn't see any suture lines but when I looked under the microscope, there they were!  Here are a few photos from the microscope.  Hopefully they show up in the photos.

 

[abyssunder]

Thank you for the new pictures. And yes, the suture lines are there. They look ceratitic type, to me.

[Ludwigia]

I agree wholeheartedly again with abyssunder. It could very well be a Meekoceras. Check out the websites here  and there

[Sagebrush Steve]

Thanks, everyone, you have been a great help.  I was pretty sure about the Mucrospirifer but I didn't have much hope for identifying the ammonite.  Meekoceras is a good possibility.  Mine is just a bit on the small side but I guess it is a microconch.

[abyssunder]

I agree with Roger, Meekoceras would be a good candidate. If you want to read more about the genus you could check this document and compare your specimen with those described and illustrated there : J. P. Smith. 1932. Lower Triassic Ammonoids of North America. USGS Professional Paper 167.

[Sagebrush Steve]

2 hours ago, abyssunder said:

I agree with Roger, Meekoceras would be a good candidate. If you want to read more about the genus you could check this document and compare your specimen with those described and illustrated there : J. P. Smith. 1932. Lower Triassic Ammonoids of North America. USGS Professional Paper 167.

 

Thanks, abyssunder, I read the paper and decided to try to trace out the sutures on my ammonite and compare them to the ones shown for Meekoceras gracilitatis on Plate 12 of the paper.  It was a little difficult to trace them out, but I was able to trace 3 sutures reasonably well.  I normalized them and fit them over each other and compared them to the suture line shown on the paper.  Pretty good fit!

 

 

[Ludwigia]

9 hours ago, Sagebrush Steve said:

Mine is just a bit on the small side but I guess it is a microconch.

 

"Microconch" is a term which applies to what are thought to be the male members of a species, which is not necessarily the case with your specimen. What you have there are the inner whorls of the phragmocone.

[Sagebrush Steve]

7 hours ago, Ludwigia said:

 

"Microconch" is a term which applies to what are thought to be the male members of a species, which is not necessarily the case with your specimen. What you have there are the inner whorls of the phragmocone.

Thanks, yes, I knew that microconch refers to the male members, but I do have questions.  How do you know it is only the inner whorls?  Is it because the end of the aperture is shaped like a suture?  Would you expect it to be different if it included the living chamber?  Also, I am still learning the terms.  Does the phragmocone end where the living chamber begins, or does it include the living chamber?

[doushantuo]

Some sort of Pavlovian reflex makes me think of the following:

phragmocone

[doushantuo]

dimorphism(fairly recent review):

 

[Ludwigia]

2 hours ago, Sagebrush Steve said:

How do you know it is only the inner whorls?  Is it because the end of the aperture is shaped like a suture?  Would you expect it to be different if it included the living chamber?  Also, I am still learning the terms.  Does the phragmocone end where the living chamber begins, or does it include the living chamber?

 

As long as you can see at least the impressions of the suture lines on the shell or mold, then you know you've still got a phragmocone in your hands. Yours also shows a septal wall in the closeup of the aperture. Doushantu's link is a little complicated, but to put it in a nutshell, the phragmocone was the buoyancy apparatus of the ammonite. Here's a link which explains it in simple terms. The body chamber begins, as you surmise, where the phramocone ends, and has no suture lines on it, which allows one to differentiate between the two.

[Sagebrush Steve]

Thanks, doushantuo and Ludwigia, this information helps. And I now have plenty of reading for a long winter night!

[abyssunder]

17 hours ago, Sagebrush Steve said:

 

Thanks, abyssunder, I read the paper and decided to try to trace out the sutures on my ammonite and compare them to the ones shown for Meekoceras gracilitatis on Plate 12 of the paper.  It was a little difficult to trace them out, but I was able to trace 3 sutures reasonably well.  I normalized them and fit them over each other and compared them to the suture line shown on the paper.  Pretty good fit!

You did it very well, with the suture lines. My thought was also that your specimen could be M. gracilitatis. There are really nice plates in the mentioned document. Well done, Steve!