Email correspondences with various Paleontologists on the subject of the Mystery Fossil

Anette Högström, Visiting PRI from the Swedish Museum of Natural History
Machaeridian Ruleout

-----Original Message-----
From: Anette Hogstrom
Sent: Saturday, December 04, 1999 4:19 PM
To: Bill Heimbrock
Subject: Re: Mystery Plate from the Cincinnatian Arnheim

Dear Bill,

I got everything alright, pictures and specimens. And I also received the
image of the four plated specimen.

I can quite safely say that they're not machaeridians. They don't really
look like anything that I've seen before. I've been thinking quite a lot on
them lately in order to come up with ideas that might be worth pursuing. One
is that with your permission I'd like to show them to some colleagues and
see what their reactions are. I'm going back to Sweden on the 15th of
December and was thinking about bringing the material with me. One of them
works on early micro-vertebrates and might have seen something similar.

Would it be OK with you if I took them with me to show some people? I will
return the material to you promptly if you wish so.

One thing that always strikes me with fossils such as this is that even
though they turn out to be quite numerous where they occur, no one
recognises them as something they have seen before. These plates seem to
meet the same criteria. But I'm afraid that I don't really have any concrete
ideas about what they might be at the moment. Knowing the mineralogical
composition of the plates would most likely help.

Again my apologies for not returning your mail earlier.

Sinecerely
Anette Högström

************************************
Anette Högström
Visiting Scientist
Paleontological Research Institution
1259 Trumansburg Road
Ithaca, New York 14850-1398
USA

Carole Burrow, University of Queensland, Vertebrate Palaeontology Laboratory

----- Original Message -----
From: Carole Burrow
To: Paleonet List Server
Sent: Sunday, June 11, 2000 1:47 AM
Subject: Re: Bill's paleonet Mystery Microfossil

Dear Bill
Have you considered the possibility the microfossils are vertebrate? Your
pics look to me like they could be dermal scales bearing an ornament of 2-4
elongate ridges. Though they differ to the scales of other Upper Ordovician
verts described from the western US, some heterostracans and placoderms
from Silurian/Devonian deposits have a similar ornament. I would be happy
to look at a sample if you are willing to send it all the way to Australia.
Carole

><> ><> ><> ><> ><> ><> ><> ><> ><> ><>
Carole Burrow
Vertebrate Palaeontology Laboratory
Department of Zoology and Entomology
University of Queensland 4072 QLD
AUSTRALIA
<>< <>< <>< <>< <>< <>< <>< <>< <>< <><

-----Original Message-----
From: Bill Heimbrock on Paleonet
Sent: Sunday, June 11, 2000 8:35 AM
To: Carole Burrow on Paleonet
Subject: Re: Bill's paleonet Mystery Microfossil

Carole,

The mystery microfossils have been examined by several vertebrate
paleontologists, one of which, Ivan Sansom, specializes in microvertebrates.
Another is Glenn Storrs, of the Cincinnati Museum of Natural History and
Science. They now seriously doubt that the fossils are vertebrate material.
Fish fossils from the Upper Ordovician of the Cincinnatian are kind of the
holy grail around here. Everyone gets excited when there is a possible find
because such microfossils have not yet been located in our local layers.

Bill Heimbrock
Dry Dredgers
1621 Westwood Ave
Cincinnati, OH 45214
(513) 921-2335

-----Original Message-----
From: CAROLE BURROW
Sent: Monday, July 10, 2000 11:37 PM
To: Bill Heimbrock
Subject: mystery fossils

Dear Bill
My normal email server has been deadish for the last couple of days, so I
am using a different address to my usual one - if you have any more info
for me, it's best (I hope) to use the other address, as I rarely check
this one (just cleaned out the mailbox Jan-July!). I have been remiss in
sending a detailed reply to the receipt of your fossils; I am heading off
to a clutch of conferences tomorrow, and have been finishing off a big
paper for that. As you suspected, there is no indication of vertebrate
tissues in the fossils, and looks can be deceiving! However, the
conferences I am going to cover pretty diverse subjects, and I am sure
there will be lots of Early Palaeozoic invert people there who would be
very interested in acquiring and/or looking at your fossils, so I'll take
them with me. The conferences are actually at Orange in the west of New
South Wales; organized by Ruth Mawson and John Talent from MUCEP in Sydney
- I think you might have been sending them material as well? Perhaps
someone will recognize them yet. In any case, thanks for sending them to
me, and it's a shame they're probably not vertebrate!
Best wishes
Carole

>-----Original Message-----
>From: Bill Heimbrock
>Sent: Saturday, December 11, 1999 4:34 PM
>To: Colin D. Sumrall; Glenn Storrs; Greg Schumacher; Jack Kallmeyer;
>Rich Fuches; Roger Cuffey; Royal Mapes; Sharon St. Louis; Steve Felton
>Cc: Ivan Sansom
>Subject: Sterom found in Mystery Plates
>
>Hi All,
>
>Ivan Sansom, of the University of Birmingham, UK, has graciously made thin
>sections on the mystery "micromammoth teeth". He says he sees sterom in
>them, pointing to Echinoderm. See Email below. He says he will photograph
>the thin sections and send us some pictures via Email, which I will share
>with you.

>After receiving his Email, I broke a couple of the mystery plates, of which
>I now have an abundant supply, and I believe that I, too, can see sterom. I
>had to use my new stereo microscope with 45X magnification to see these
>sterom, which appear as small dots.
>
>Any of you that get a chance, go ahead and break a few open and have a look.
>I can replenish your supply. If this checks out, we have Echinoderm plates.
>Then the puzzle becomes.... what type of Echinoderm are they from???
>
>It looks to me like the sterom are not filling the plates entirely, which
>may suggest an internal structure. We will know more when we see the thin
>section images.
>
>Just keeping you all informed.
>
>Bill

-----Original Message-----
From: Colin D. Sumrall
Sent: Monday, December 13, 1999 8:54 AM
To: Bill Heimbrock
Subject: Re: Sterom found in Mystery Plates

Bill-

He undoubtedly thin sectioned one of the echinoderm plates that show
superb, almost dead-yesterday, stereom or else misinterpreted the
miscostructure, but the "plates" in question show no stereom of that I am
sure. I etched them out with acid and they are phosphate fills of some
structure that is as yet unknown. That is all I can tell you.

>After receiving his Email, I broke a couple of the mystery plates, of which
>I now have an abundant supply, and I believe that I, too, can see sterom. I
>had to use my new stereo microscope with 45X magnification to see these
>sterom, which appear as small dots.

Stereom is not a series of small dots, rather it is a series of holes
running through the material and it goes all of the way through. Take one
of the cyclocystoid plates and soak it in vinegar overnight and look at it
where it is broken and you will see the real stereom.

######################################

Colin D. Sumrall, PhD
Curator of Invertebrate Paleontology
Geier Collections and Research Center
Cincinnati Museum Center
1720 Gilbert Ave.
Cincinnati, Ohio 45202

-----Original Message-----
From: Colin D. Sumrall
Sent: Monday, December 13, 1999 12:30 PM
To: Bill Heimbrock
Subject: Re: Sterom found in Mystery Plates

Bill-

The attachment is what stereom really looks like. ALL of the echinoderm
plates at your site have preservation that is even better than this plate
from the Pennsylvanian of Oklahoma. In the strange bits you have there
isn't even the slightest hint of the gallery of neatly arranged holes that
ALL echinoderm plates have. The most damning piece of evidence is that the
crinoid stems, crinoid cup plates, cyclocystoid plates, and starfish plates
all have this microstructure and none of the strange bits have even the
slightest hint of true stereom.

Hope it is of some help

Sincerely

-----Original Message-----
From: Bill Heimbrock
Sent: Monday, December 13, 1999 1:01 PM
To: Colin D. Sumrall
Subject: Re: Sterom found in Mystery Plates

Thanks Colin.

After I received your first Email I broke samples I had previously soaked 24
hours in Vinegar. They included Cyclocystoid plates, Crinoid columnals,
Crinoid cup plates and the mystery plates.

The Cyclocystoid plates had a loose, big stereom pattern, forming a
sponge-like mesh.

The Crinoid stems and cup plates had a tight, smaller, more dense stereom
pattern, with some of the stereoms forming lines while others had the
sponge-like pattern.

The mystery plates did not have a distinct stereom pattern, but did have a
few diagonal lines of yellowish brown material that seemed somewhat loose or
porous.

I'll wait for the photos of the thin sections to see what Ivan had seen.
I'll pass them on to you when I get them.

Would it be okay if I forward this discussion to Ivan Sansom with a CC: to
the others on my distribution. I won't do it unless you say it is okay.

Thanks for your help!

Bill

-----Original Message-----
From: Colin D. Sumrall
Sent: Monday, December 13, 1999 1:17 PM
To: Bill Heimbrock
Subject: Re: Sterom found in Mystery Plates

Bill-

You can do whatever you wish with the info. As far as diagnoal lines are
concerned, Stereom is a series of pillars and bars that forms the three
dimentional meshwork of the plate. A few diagnoal lines is a far cry from
the perfect preservation of the rest of the plate material at the locality.
For what it is worth. Also Dave Meyer is one of the leading experts on
stereom.

######################################

Colin D. Sumrall, PhD
Curator of Invertebrate Paleontology
Geier Collections and Research Center
Cincinnati Museum Center
1720 Gilbert Ave.
Cincinnati, Ohio 45202

-----Original Message-----
From: Joe H. Marak
Sent: Thursday, January 27, 2000 11:10 AM
To: Bill Heimbrock
Subject: Re: Mystery Fossil

Bill,
Thanks for making your pictures available, I do not remember seeing
anything similar. I checked with Wayne Martin who has studied many a
sedimentary rock thin section and he hadn't seen anything like your specimens.
I took a quick peek in our collections room and was amazed to see how few
Lyrodesma were there. Fortunately, there are several specimens exhibiting
teeth. Hope they will be good enough to help with your problem.
I look forward to visiting with you and the rest of the Dredgers Saturday!
Joe

-----Original Message-----
From: joseph g carter
Sent: Tuesday, June 20, 2000 7:27 PM
To: Bill Heimbrock
Subject: Re: Calcitized clams

Bill, Your plan sounds great. Regarding the mystery fossil, my guess is that
the hinge looks trigonioid, perhaps schizodont, although that would be a very
appearance of schizodont trigonians! Any shell exteriors? Best wishes - Joe
Carter

-----Original Message-----
From: Phillip Bigelow
Sent: Thursday, June 08, 2000 7:48 PM
To: Bill Heimbrock
Subject: Re: Mystery Fossil

Bill,
Now you have got me obscessed with those fossils too!
Because of their ubiquity, they are probably some common fossil (or part of a
fossil) that will make you say "Duh!" when you find out what they, but just in
case they are something interesting, I recommend you subscribe to the paleonet
mailing list and repost your message there. Since you have a lot of this stuff,
offer to send some material out for free.
Instructions for subscribing to paleonet mailing list can be found at:

http://www.ucmp.berkeley.edu/Paleonet/Listservers/PaleoNet.Html

Good luck, and if you ever get a positive I.D., let us know.

<pb>

-----Original Message-----
From: Prof. Willi Ziegler
Sent: Wednesday, June 14, 2000 7:38 AM
To: Bill Heimbrock
Subject: mystery fossils

Hallo,
I have read with interest your remarks on the mystery fossils of the
Ordovician in the Paleonet, but I was not able to download your
internet story with the illustrations. However, I would suggest that
you compare your material with the fotografs in a paper by
Guenther C.O. Bischoff (1973): On the nature of the conodont animal.-
Geologica & Palaeontologica, vol.7, pp.147-174, 1 text-fig, 1 tabl.,
6 pls., Marburg.
Bischoff, one of the early pioneers of conodont research who died
recently , described in his paper calciumphosphatic bar- and
plate-like structures from early paleozoic microfaunas. He
interpreted them as conodont-bearing elements, and believed that
some of them exhibit morphological features characteristic of the
conulariid test. The conodonters did not accept his theory of the
conulariid affinity.
However, the paper might be a source for a comparison.
Best wishes
Willi Ziegler

----- Original Message -----
From: Ray Gildner
To: Bill Heimbrock
Sent: Friday, June 09, 2000 2:16 PM
Subject: Mystery fossil

They don't happen to be mono-crystalline calcite, do they? Something about
these specimens is saying to me the word "Echinoderm." If they are
echinoderm pieces, I'd expect them to be monocrystalline calcite... just a
hunch

Yours,
Ray Gildner

----- Original Message -----
From: Bill Heimbrock
To: Ray Gildner
Sent: Friday, June 09, 2000 3:36 PM
Subject: Re: Mystery fossil

Hi Ray!

Ivan Sansom from the Univ. of Burmingham, UK has done thin sections and
claims to see stereom, which is a tell-tale microstructure for Echinoderms.
However, I have been assured emphatically by Colin Sumrall of the Cincinnati
Museum of Nat. Hist. & Sci., who specializes in Edrioasteroidea and other
problematic Echinoderms that my mystery fossils are not Echinoderm. He says
that all the Echinoderm material in this layer have their stereom
exceptionally well preserved. He has broken many samples of my mystery
fossil and has found no such stereom.

I believe the mystery fossils are preserved in phosphates. I am thinking
that these phosphates leave surface impressions of fossils such as
pelecypods and inarticulate brachiopods on crinoid collumnals.

I may have found a couple of examples of this in the same "fossil hash" as
the mystery fossils.

See example #1 at http://home.cinci.rr.com/billheim/crinrid3.jpg
See example #2, side#1 at http://home.cinci.rr.com/billheim/crinr2a2.jpg
See example #2, side#2 at http://home.cinci.rr.com/billheim/crinr2b2.jpg

I have not seen Ivan Sansom's thin sections, but it is possible these
mystery fossils are the surfaces of two animals, showing only
the phosphates left behind. In the case of my pelecypod hinge teeth
hypothesis, perhaps occasionally a crinoid collumnal gets stuck between
hinge teeth after these animals are dead but before the phosphates form.

More work needs to be done before these issues are resolved.

Thanks for your feedback, Ray!

Bill Heimbrock

----- Original Message -----
From: Ray Gildner
To: 'Bill Heimbrock'
Sent: Friday, June 09, 2000 3:58 PM
Subject: RE: Mystery fossil

Bill,

Well, harumph... The tight interlocking of the mystery bits had me leaning
towards crinoid columnals. I think (but am not sure) that there are examples
of columnals with non-parallel surfaces. Good luck, and thanks for the
response!

Yours,
Ray Gildner

----- Original Message -----
From: Bill Heimbrock
To: Ray Gildner
Sent: Friday, June 09, 2000 4:09 PM
Subject: Re: Mystery fossil

Ray,

I know exactly what you are talking about. I see these fragments of crinoid
stems in this "sand" layer where the centers of the columnals are gone and
the circular section with the interlocking ridges are all that remains. Many
are partials with a crescent shape. The lines in these cases all point to a
singe point in space that was the center of the columnal. Not only do they
appear as quite distinctly different in the fossil hash, but I can rule them
out because the interlinking lines on crinoid columnal are straight, albeit
radial, while the mystery fossil's lines ridges are curved.

Nice idea though.

Thanks!

Bill

-----Original Message-----
From: Rich Fuchs
Sent: Monday, November 01, 1999 5:27 PM
To: Bill Heimbrock
Subject: Re: Mystery Fossils

I put a piece of the rock containing a broken plate into some 5% hydrochloric acid and left it overnight. There was no sign of the plate after 24 hours. However, I found what might be a piece of a plate in the residue. I've placed it in some more acid to see what happens. Right now, it appears the plate are not acid resistant for long periods.

-----Original Message-----
From: Rich Fuchs
Sent: Tuesday, November 02, 1999 4:21 PM
To: Bill Heimbrock
Subject: Re: More about the mystery plates

Bill

I tested the plate with 5% hydrochloric acid and the results are not
conclusive, yet. Will do one more test. Right now it appears that the
plates might be acid resistant.

Found ten plates on one of the rocks I brought home. This included a double
(possibly triple) and four plates together.

Rich

-----Original Message-----
From: Rich Fuchs
Sent: Tuesday, December 07, 1999 9:31 PM
To: Bill Heimbrock
Subject: Re: Mystery Micromammoth Teeth Update

Bill

I've shown the plates to couple of biologists and they are just as stymied
as the rest of us.

I still don't think these have anything to do with bryozoans, because of the
overlapping plates in the multiples. I could be wrong.

Rich

-----Original Message-----
From: Schumacher, Greg
Sent: Friday, October 29, 1999 8:20 AM
To: Bill Heimbrock
Subject: Plates with no name

Greetings Bill,

I spent last Tuesday with Bob Frey and Steve Felton looking at an Arnheim
section in Brown County. Excellent weather made for a wonderful day which
we all enjoyed.

I asked Bob about the plates you found. He was not sure, but suggested some
sort of echinoderm. Sorry, I don't have more to report.

Take care
Greg

-----Original Message-----
From: Ivan Sansom
Sent: Thursday, November 25, 1999 2:18 PM
To: billheim@sprynet.com
Subject:

Dear Bill

Thanks for sending me the specimens of the "mystery microfossil".
Certainly on first appearance the ornament looks similar to some
Ordovician fish scales that I have been studying from the frontal
range of the Rockies. However, the presence of ridges on both
sides is a bit curious. I'll section one or two specimens and see if
the hard tissues are preserved and if these tell us anything about
their classification. I'll be in touch as and when I've got the thin
sections finished.

Cheers

Ivan

Dr. Ivan J. Sansom
Lecturer in Palaeobiology
School of Earth Sciences
University of Birmingham
Edgbaston
Birmingham B15 2TT
UK

-----Original Message-----
From: Ivan Sansom
Sent: Thursday, December 09, 1999 12:44 PM
To: Bill Heimbrock
Subject:

Bill,

I've just had a look at the thin sections I've made of your
specimens, and the core of them seems to be formed from sterom,
so I'd suggest that they are secondarily phosphatised echinoderm
plates. I'll try and get around photograph some of the sections and
scan the images in and email them to you.

Cheers

Ivan

Dr. Ivan J. Sansom
Lecturer in Palaeobiology
School of Earth Sciences
University of Birmingham
Edgbaston
Birmingham B15 2TT
UK

-----Original Message-----
From: Ivan Sansom
Sent: Wednesday, June 21, 2000 2:26 PM
To: Bill Heimbrock
Subject:

Bill

I'll scan in the illustrations of the stereom in the next couple of
weeks. The point I've made about the presence of stereom is that
these specimens are secondarily phosphatized, destroying a lot of
the original fabric - therefore stereom is not present in all of the
specimens, so simply breaking open a specimen will not reveal
stereom with any degree of regularity.

Cheers

Ivan

Dr. Ivan J. Sansom
Lecturer in Palaeobiology
School of Earth Sciences
University of Birmingham
Edgbaston
Birmingham B15 2TT
UK

-----Original Message-----
From: Ivan Sansom
Sent: Friday, August 18, 2000 9:17 AM
To: Bill Heimbrock
Subject: Re: Mystery Fossil Update

Bill

I finally got round to scanning in the pictures of stereom from your
mystery fossils, please feel free to place them on your website and
mention their existence to whoever. As you can see 1 and 2 are
probably the best - and that there has been a lot of alteration, the
fine grained brown "crud" is common in my experience where
specimens have undergone secondary phosphatization, and there
are some well developed crystals of apatite in 3.

Ivan

Dr. Ivan J. Sansom
Lecturer in Palaeobiology
School of Earth Sciences
University of Birmingham
Edgbaston
Birmingham B15 2TT
UK

-----Original Message-----
Sent: Friday, June 16, 2000 8:41 AM
Subject: Re: paleonet Mystery Microfossil

Dear Bill,

Your great package arrived yesterday. I appreciate your promptness and
the diversity of material you sent along. I've already picked a few more
X-Fossils from grain-size #3.
1. My colleague, Rich Mooi, here at the Academy is the foremost
authority of echinoid evolution in the country, and our examination of
the plates eliminates them as echinoid fossils, certainly not feeding
structures. We do have to comment however on the amazing preservation of
the cyclocystoid skeletal elements. We have never seen the porous,
trebicular structure of the elements preserved in Paleozoic echinos
before.
2. These plates are body fossils and not molds or impressions.
3. They are not brachiopod internal molds, although they superficially
resemble them and all the other columnar colonial structures in this
fossil hash.
4. I do not support any of the other conjectures you list in your
letter, except an outside possibility of a vertebrate element, further,
Withers' (1926) monograph on Macharidia, and the genus Turrilepas does
show show similarities to the X-Fossil.
5. My colleages and I do agree the specimens do possess a strong
molluscan feel.
6. I'm going to take some thin-sections, that should help settle a
number of issues.

Thank you for introducing me to this most interesting fossil, I will do
my utmost to deduce its' provenance.

Dawn
-----Original Message-----
Sent: Wednesday, June 21, 2000 12:51 PM
To: Paleonet List Server
Subject: Re: paleonet Mystery Microfossil

Dawn,

Thank you very much for the insightful comments! I have some questions and
feedback.

> 1. My colleague, Rich Mooi, here at the Academy is the foremost
> authority of echinoid evolution in the country, and our examination of
> the plates eliminates them as echinoid fossils, certainly not feeding
> structures.

Agreed. Let me know, though, if you see stereom in your thin sections.

> We do have to comment however on the amazing preservation of
> the cyclocystoid skeletal elements. We have never seen the porous,
> trebicular structure of the elements preserved in Paleozoic echinos
> before.

I am glad that you and RIch find that interesting. It has excited every
Echinoderm person to receive samples. I have given Colin Sumrall,
specializing in Edrioasteroids at the Cincinnati Museum, approx 10 thousand
of the cyclocystoid plates. He exclaimed that it is probably the largest
collection of Cyclocystoids (mostly Zygocycloides) anywhere! I gave him all
I had to date. If Rich would like a larger supply than what I sent, I would
be happy to collect more for him.

> 2. These plates are body fossils and not molds or impressions.

Can you elaborate on what you and Rich saw to conclude that they are not
molds or impressions?

> 3. They are not brachiopod internal molds, although they superficially
> resemble them and all the other columnar colonial structures in this
> fossil hash.

I agree. Any resemblance to the wavy edges of the Zygospira brachiopods are
apparently superficial. The columnar colonial structures, which are bryozoan
steinkerns, have a close association with these mystery fossils. The
multi-plate specimens of the mystery fossils seem to be most often found in
portions of fossil hash in rock that are loaded with these bryozoans. This
striking association is what prompted me to contact Roger Cuffey, who feels
these mystery fossils are not bryozoan steinkerns. He did, however, identify
several other phosphatic masses that had ridges as bryozoan.

> 4. I do not support any of the other conjectures you list in your
> letter, except an outside possibility of a vertebrate element

The vertebrate diagnosis is not yet a rule-out, but so far, Ivan Sansom of
the Univ of Burmingham, UK and Glenn Storrs of the Cincinnati Museum have
serious doubts.

I have just shipped some samples to Ruth Mawson, of MacQuarie University in
Australia, who has PhD students studying fish parts and am preparing a
shipment to Carole Burrow of the Vertebrate Paleo Lab at the Univ of
Queensland, also in Australia.

For the information of the Paleonet readers, samples are also being prepared
for shipping to Bruce Robertson of New Orleans and Darren Garrison of
Peizer, South Carolina.

> further Withers' (1926) monograph on Macharidia, and the genus Turrilepas
does
> show show similarities to the X-Fossil.

Got it. Read it. I had thought that they could be plates of Lepidocoleus,
which are common in the Arnheim. It would be unusual preservation, if so. I
sent samples to Anette Högström while she was visiting PRI from the Swedish
Museum. Anette is studying problematica and specializes in Machaeridia. She
replied back assuring me that these mystery fossils are definitely not
Machaeridia of any kind. She took some samples back to Sweden to show around
and have not heard back from her.

> 5. My colleages and I do agree the specimens do possess a strong
> molluscan feel.

Maybe pelecypod? I'm still leaning toward hinge teeth. I am talking with Joe
Carter of the Univ. of North Carolina. He's studying clam microstructure and
I am planning to collaborate with him to further investigate the hinge teeth
possibility.

Thanks very much, Dawn, for having a look at these things and planning to do
thin sections on them. Let me know what you see.

I'll reply offline to you regarding the Ostrocod information.

Bill Heimbrock
Dry Dredgers
1621 Westwood Ave
Cincinnati, OH 45214
USA
billheim@cinci.rr.com
http://home.cinci.rr.com/billheim/mystery2.htm

> ----- Original Message -----
> From: Dawn Peterson
> To: Bill Heimbrock
> Sent: Wednesday, June 21, 2000 12:05 AM
> Subject: Mystery fossils
>
> Dear Bill,
>
> I have sectioned one of our mystery fossils and it is unlike anything I
> have seen. Because of the size, I had to grind a face by hand rather
> than use our thin-section saw. What I found was a thin outer "shell" or
> rind while, internally, I saw a series of a few tubular structures
> running perpendicularly to the exterior grooved channels. I was unable
> to observe the terminal structure on any of these "tubes". The
> interstices between these structures appeared to be sediment-filled (?).
> No trace of trebecular structure could be observed.
> I am still searching the literature and discussing these specimens with
> my colleagues. Bear with me.
>
> Best regards,
>
> Dawn Peterson

-----Original Message-----
From: Dawn Peterson
Sent: Wednesday, June 21, 2000 4:04 AM
To: Bill Heimbrock
Subject: Re: Mystery fossils

Bill Heimbrock wrote:
>
> Thanks Dawn.
>
> Does it look like the tubes are made of the same material as the outer rind?
>
> Bill

> ----- Original Message -----
> From: Dawn Peterson
> To: Bill Heimbrock
> Sent: Wednesday, June 21, 2000 2:13 AM
> Subject: Re: Mystery fossils
>
> Dear Bill,
>
> The tubes are hollow. Despite my colleagues' doubt that they are
> echinoderm, I still think they need to be considered.

Dear Bill - The outer "shell" is, as you know a pale tan, while the
"tube-like structures" are brownish-red. However, there are diagenetic
effects to consider. It is highly possible we not be seeing the original
coloration of either structure. One other note: The outer "shell" is
three or four times thicker than the "tube-like structures".

Ciao,

Dawn Peterson