Jump to content

Lycopsid identification help needed - Sigillaria?


Kato

Recommended Posts

At first sight out in the back country I thought I had stumbled on some calamite sections. After cleaning up some specimens at home, I am now leaning more toward some other Lycopsid. Perhaps Sigillaria?

 

@paleoflor

 

DarkSig3.thumb.jpg.96952302d715b221ca9dcd32619d205f.jpg

 

More photos to follow

DarkSig3.jpg

Link to comment
Share on other sites

1 hour ago, Kato said:

At first sight out in the back country I thought I had stumbled on some calamite sections.

Stay there. That's what it is.

  • I found this Informative 3
Link to comment
Share on other sites

I agree with the Calamites ID. The last photo shows where the nodes that are so often used to identify Calamites would have been.

  • I found this Informative 2
Link to comment
Share on other sites

12 hours ago, Rockwood said:

Stay there. That's what it is.

@Rockwood     

 

If my memory serves me correctly there is essentially no outer layer preservation of calamites. What is showing in these specimens is vascular tissue?

Link to comment
Share on other sites

Agree with Calamites; the nodes are clearly visible and the ribs alternate at the nodal lines. Based on the branch scar in the last photograph, I'd even be quite comfortable calling that specific specimen "Calamites subgenus Diplocalamites". Perhaps you can compare your specimen with Calamites carinatus, though the preservation is rather atypical here. 

 

  • I found this Informative 3

Searching for green in the dark grey.

Link to comment
Share on other sites

3 hours ago, Kato said:

@Rockwood     

 

If my memory serves me correctly there is essentially no outer layer preservation of calamites. What is showing in these specimens is vascular tissue?

I believe this is a pith cast, so those would be impressions of the vascular tissues, yes.

As with most plants, they have been preserved in a number of other ways though.

  • I found this Informative 1
Link to comment
Share on other sites

2 hours ago, paleoflor said:

Agree with Calamites; the nodes are clearly visible and the ribs alternate at the nodal lines. Based on the branch scar in the last photograph, I'd even be quite comfortable calling that specific specimen "Calamites subgenus Diplocalamites". Perhaps you can compare your specimen with Calamites carinatus, though the preservation is rather atypical here. 

 

@paleoflor

 

I was able to verify an oppositional branch scar node to the one photographed on that piece. Theoretically, this would begin to align with your thought of Diplocalamites. From your suggestion I researched online and read that 

 

Diplocalamites has two opposite branch scars at every node. Per node they turn by 90 degrees.

 

diplocalamites.png.d600f90b594b86f28c84fbba05b01912.png

 

Unable to verify the pattern above clearly whereby the branch scars turn by 90 degrees per node. Yet, there was another section with the opposite branch scars. 

Link to comment
Share on other sites

If the opposite branch scars occur only sporadically, rather than every node, you might want to consider subgenus Stylocalamites too (note these are all "morphogenera" anyway).

  • I found this Informative 2

Searching for green in the dark grey.

Link to comment
Share on other sites

Fossil plant names are complicated, but it's necessary because many detached parts preserve in ways that represent different aspects of the original plant. 

  • I found this Informative 1
Link to comment
Share on other sites

1 hour ago, paleoflor said:

If the opposite branch scars occur only sporadically, rather than every node, you might want to consider subgenus Stylocalamites too (note these are all "morphogenera" anyway).

@paleoflor  @Rockwood

 

Given the small size of the calamite would it be reasonable to expect not much branching in general? The two oppositional branch scars nodes were separated by a node that a break and material breakdown occurred making it unlikely to find branch scars. The two nodes having scars are aligned as shown in the diagram above. The 2 nodes with scars are skewed to the far end of the specimen which is 54" in length.  Given the repetition of the pattern in every other node I feel your diplocalamites is correct. 

 

Once I get a proper pry bar I'm going back with a small shovel, a 2lb hammer and a chisel to see if I can find more of the calamite.  i.e. maybe the rhizome?

 

So....two oppositional pairs with a broken node in-between and then nothing discernible below that. Perhaps some suggestions of branch scars but not unequivocable.

 

diplocalamites_modified.png.f93423fc444886e3bfffe5aa6f4a43f2.png

 

Link to comment
Share on other sites

Most representations of annularia that I'm familiar with are on branches that must be at least one order out, so I would expect the standard bottle brush configuration to be normal here. 

Link to comment
Share on other sites

12 minutes ago, Rockwood said:

Most representations of annularia that I'm familiar with are on branches that must be at least one order out, so I would expect the standard bottle brush configuration to be normal here. 

@rockwood @paleoflor

 

132976239095952-med.jpg.1062c0fb426311216179943870ccba01.jpg

 

 

image.thumb.png.438e26af24a3208b233511033cc7f05c.png

  • I found this Informative 2
Link to comment
Share on other sites

The reconstructions of the morphological subgenera are quite illustrative, but more recent research has shown the calamiteleans showed rather more variable growth (e.g. Rössler and Feng, 2012). Note palaeobotanical nomenclature generally suffers from the fragmented nature of the fossils. The specimen you encountered is relatively large, so it would be interesting to look at the positions of the branch scars in detail, but I wouldn't be surprised if it doesn't fit any of the above morphological subgenera. Good luck with excavating the remainder! 

  • I found this Informative 3

Searching for green in the dark grey.

Link to comment
Share on other sites

1 hour ago, Rockwood said:

Makes perfect sense. Plants always have to play the hand they are dealt.

@Rockwood @paleoflor

 

Thank you for offering your insight and time.  I appreciate your expertise and enjoy reading the articles paleoflor suggests.

 

Wow! Reading the suggested article....10 meters of trunk found. It appears I have a long ways to go at <2 meters. Given the apparent diameter of this small trunk it may have only been 4-5 meters tall?

 

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...