FINAL(?) IDENTIFICATION OF THE FALSE EDESTUS FROM THE HUNSRÜCK SLATE: PROTOVIRGULARIA (A TRACE FOSSIL)

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MAY 2020 | TRILOBITE TAL ES 23
FINAL(?) IDENTIFICATION OF THE FALSE EDESTUS
FROM THE HUNSRÜCK SLATE: PROTOVIRGULARIA
(A TRACE FOSSIL)
by Wayne Itano –In two previous articles in Trilobite Tales (Itano, 2019a, 2019b), I told of finding a
fossil labeled as an Edestus tooth whorl (Edestus being a fossil shark) in the collections of the Natural
History Museum in London in December 2011 and of my subsequent attempts to determine precisely
what it was. It clearly was not a shark fossil. Figure 1 shows the fossil, which is from the Lower
Devonian Hunsrück Slate of Germany. I have received many opinions as to its identity. Opinions have
differed even as to whether it is a body fossil or a trace fossil.
What is it? Body fossil candidates:
No one whom I have consulted believes that the Hunsrück fossil is an edestoid tooth whorl or even
any kind of vertebrate fossil. Figure 2 shows an example of an edestoid tooth whorl, this one being a
partial tooth whorl of Helicoprion bessonowi. The morphology (shape) of the Hunsrück fossil is not like
that of any known shark teeth. Moreover, there is no sign of tooth-like material. If such material is
present, then it is buried in the matrix. An x-ray image would be illuminating.
It has been suggested that the
Hunsrück fossil is a lepidocoleid
machaeridian (a kind of armored
worm). If it is, then an x-ray
image would show details of the
armored plates and also of the soft
body parts, since soft parts are
preserved with pyrite replacement
in this formation. These
organisms are known to be
present in the Hunsrück
(Högtröm, Briggs, & Bartels,
2009). Figure 3 shows an
example of a ledidocoleid
machaeridian from the Lower
Devonian of Oklahoma.
There is some resemblance of the
Hunsrück fossil, in the external
appearance, to a loosely coiled
ammonoid. Figure 4 is a
reconstruction of Metabactrites
fuchsi, an ammonoid known from
the Hunsrück Slate (De Baets,
Klug, Korn, Bartels, &
Poschmann, 2013). However, on
closer examination, the “ribs” of
the Hunsrück fossil (see Figure 1)
are unusual for a Devonian
Figure 1. Mystery fossil from the Hunsrück
Slate labeled as an Edestus tooth whorl.
Specimen number NHMUK PV P.16195.
Scale units are cm. Photo: W. Itano.
Figure 2. Incomplete tooth whorl of
Helicoprion bessonowi from the Permian of
Kazakhstan, PIN 1988/38B. Photo: W. Itano.
Figure 3. Lepidocoleus sp., an armored
worm, from the Lower Devonian of Coal
County, Oklahoma. Photo by George P.
Hansen. Used with permission.
Figure 4. (right) Reconstruction of
Metabactrites fuchsi, a Devonian
ammonoid. Artwork by Christian Klug. Used
with permission.

24 TRILOBITE TALES | MAY 2020
ammonoid, being irregular, varying in appearance from one part
to the other, and containing angular bends. All ammonoids
currently known from the Hunsrück Slate (De Baets et al., 2013)
have more regular, gently curved ribs, as in Figure 4.
The staff of the Natural History Museum were kind enough to
provide an x-ray image of the Hunsrück fossil (Itano, 2019a, fig.
7). There was an image, but it was rather fuzzy and indistinct.
This seems to rule out any kind of body fossil. The question of
why there is even a fuzzy image will be dealt with later. If it is not
a body fossil, then it seems it must be a trace fossil.
What is it? Trace fossil candidates:
It has been suggested that the Hunsrück fossil is a trace fossil
belonging to the ichnogenus Protovirgularia M’Coy, 1850.
(Ichnogenera and ichnospecies are names used to classify trace
fossils, in analogy to ordinary genera and species used to classify
plants and animals.) Protovirgularia is a trace fossil consisting of an
unbranched trail, straight or slightly curved, with a median line
and bilaterally symmetrical, narrow appendages (Han & Pickerell,
1994). Figure 5 shows one of M’Coy’s type specimens. Another
example is shown in Figure 6. This ichnogenus has an interesting
history of its own. Although now established as a trace fossil,
M’Coy (who sometimes spelled his name McCoy) considered it to
be a body fossil of an animal like the modern Virgularia, which is
a soft coral (see Figure 7). It seems that mistaking trace fossils for
body fossils is a practice with a long history. It is now thought that
Protovirgularia is a trace made by a moving bivalve (Ekdale &
Bromley, 2001; Han & Pickerell, 1994).
Trace fossils in the Hunsrück Slate
Trace fossils in the Hunsrück Slate have been the subject of
several studies (e.g., Richter, 1931, 1941; Seilacher, 1960;
Seilacher & Hemleben, 1966; Sutcliffe, Briggs, & Bartels, 1999).
Of the various photographs and drawings of trace fossils in these
articles, one (Figure 8) illustrated by Richter (1941) resembles the
Hunsrück Slate fossil that is the subject of this article. Sutcliffe et
al. (1999) depicted a trace fossil of this kind in their fig. 3C6.
They interpreted the bulbous feature at one end as a resting trace
and the rest of the trace as showing the motion of the organism
that created the trace forward and upward out of the sediment.
There is a close correspondence of Figure 8 to the Hunsrück
`Edestus’ fossil (Figure 9).
Why is there a visible x-ray image?
The final question is why a trace fossil would show up in an x-ray
image, even if rather indistinct. After all, one would expect the
trace fossil to be made up of the same material as the surrounding
matrix. In the Hunsrück Slate, organic material undergoes
pyritization (Kühl, Bartels, Briggs, & Rust, 2012, p. 14). This
makes the former organic material opaque to x-rays, due to the
Figure 5. Syntype of Protovirgularia dichotoma
from the Ordovician of Scotland. Specimen
number SM A 45582 (British Geological Survey,
2020). This work is licensed under a Creative
Commons Attribution-NonCommercial-
ShareAlike 3.0 Unported License.
Figure 6. An example of the trace fossil
Protovirgularia dichotoma, from the
Pennsylvanian of Washington County, Arkansas
(Ekdale & Bromley, 2001, fig. 2). Copyright John
Wiley and Sons. Used with permission.
Figure 7. The modern Virgularia sp. (Purple Sea
Pen, a soft coral). Photo credit Nick Hobgood.
This file is licensed under the Creative
Commons Attribution-Share Alike 3.0 Unported
license.

MAY 2020 | TRILOBITE TAL ES 25
presence of iron. Gastropods are
known to secrete mucus, which
aids in their locomotion on the
surface of the substrate (Denny,
1980). Bivalves (or whatever
organism made the traces) might
also secrete mucus, whether to
aid in their locomotion or simply
as an incidental action. The
mucus (or other secreted organic
material) could then have been
partially replaced by pyrite,
which could have resulted in the
indistinct x-ray image.
Conclusion
In my opinion, the x-ray image,
with its lack of any detail of
animal body parts, provides good evidence that the Hunsrück fossil is
a trace fossil. The physical shape is like that of the ichnogenus
Protovirgularia. The featureless structure at one end of the trace
resembles the ones identified as resting traces in other examples of
Hunsrück Slate Protovirgularia. The visibility of the x-ray image is likely due to mucus secreted by the
tracemaking organism acting as a site for pyritization.
Acknowledgments: I thank Christian Klug for providing the drawing of Metabactrites fuchsi. I thank
Martha Richter and Emma Bernard (NHMUK) and Oleg Lebedev (PIN) for access to collections. I
thank George P. Hansen for the photograph of Lepidocoleus.
Abbreviations: NHMUK: Natural History Museum, London, UK; PIN: Paleontological Institute of the Russian Academy of
Sciences, Moscow, Russia; SM: Sedgewick Museum, Oxford University, Oxford, UK.
References
British Geological Survey. (2020). Fossil specimen : SM A 45583 – Syntype. Retrieved 25 February 2020, from
http://www.3d-fossils.ac.uk/fossilType.cfm?typSampleId=20002027.
De Baets, K., Klug, C., Korn, D., Bartels, C., & Poschmann, M. (2013). Emsian Ammonoidea and the age of the Hunsrück
Slate (Rhenish Mountains, Western Germany). Palaeontographica, Abteilung A: Palaeozoology - Stratigraphy, 299(1-6), 1-113.
Denny, M. (1980). The role of gastropod mucus in locomotion. Nature, 285, 160-161.
Ekdale, A. A., & Bromley, R. G. (2001). A day and a night in the life of a cleft-foot clam: Protovirgularia-Lockeia-
Lophoctenium. Lethaia, 34, 119-124.
Han, Y., & Pickerell, R. K. (1994). Taxonomic reassessment of Protovirgularia M'Coy 1850 with new examples from the
Paleozoic of New Brunswick, eastern Canada. Ichnos, 3, 202-212. https://doi.org/10.1080/10420949409386389
Högtröm, A. E. S., Briggs, D. E. G., & Bartels, C. (2009). A pyritized lepidocoleid machaeridian (Annelida) from the Lower
Devonian Hunsrück Slate, Germany. Proceedings of the Royal Society B, 276, 1981-1986. https://doi.org/10.1098/rspb.2008.1875
Itano, W. M. (2019a). Two Lagerstätten and a false Edestus. Trilobite Tales, 37(1), 17-20.
Itano, W. M. (2019b). Update to `Two Lagerstätten and a false Edestus’ (Maybe it is an ammonoid, after all!). Trilobite Tales,
37(3), 19.
Kühl, G., Bartels, C., Briggs, D. E. G., & Rust, J. (2012). Visions of a Vanished World. New Haven,
CT: Yale University Press. https://yalebooks.yale.edu/book/9780300184600/visions-vanished-world
Figure 8. (above left) Protovirgularia trace
fossil from the Hunsrück Slate (Richter,
1941, fig. 5). The bulbous resting trace and
the trace made by the motion of the
tracemaking organism are labeled.
http://www.schweizerbart.de/senckenberg.
Used with permission.
Figure 9. (above right) `Edestus’ fossil
from the Hunsrück Slate. The bulbous
resting trace and the moving trace are
labeled. Scale units are cm. Photo: W. Itano.
– continued on next page

26 TRILOBITE TALES | MAY 2020
M'Coy, F. (1850). On some new genera an species of Silurian Radiata in the collection of the University of Cambridge.
Annals and Magazine of Natural History, 6, 270-290. http://hdl.handle.net/2027/njp.32101079668263
Richter, R. (1931). Tierwelt und Umwelt im Hunsrückschiefer; zur Entstehung eines schwarzen Schlammsteins.
Senckenbergiana, 13, 299-342.
Richter, R. (1941). Fährten als Zeugnisse des Lebens auf dem Meeres-Grunde. Senckenbergiana, 23, 218-260.
Seilacher, A. (1960). Strömungszeichen im Hunsrückschiefer. Notizblatt des Hessichen Landesamtes für Bodenforschung zu
Wiesbaden, 88, 88-106.
Seilacher, A., & Hemleben, C. (1966). Beiträge zur Sedimentation und Fossilführung des Hunsrückschiefers: 14. Spurenfauna
und Bildungstiefe der Hunsrückschiefer (Unterdevon). Notizblatt des Hessichen Landesamtes für Bodenforschung zu
Wiesbaden, 94, 40-53.
Sutcliffe, O. E., Briggs, D. E. G., & Bartels, C. (1999). Ichnological evidence for the environmental setting of the Fossil-
Lagerstätten in the Devonian Hunsrück Slate, Germany. Geology, 27(3), 275-278.
Copyright © 2020 Wayne Itano. All rights reserved.
PaleoZone Activities
The PaleoZone has not met for two months, because of the social
distancing order in Colorado. However, members have been working
on several fossil-related activities at home. Last month, they were
given the instructions from April’s Trilobite Tales to construct straight
nautiloid models out of paper. Below are two of their creations.
We hope to be able to meet again this month on Sunday, May 17.
In the meantime, we will have additional activities for the PaleoZone members to do at home.
The PaleoZone is WIPS’ program
for families with children
elementary school age and older.
The group meets on the third
Sunday of each month at the
Dinosaur Ridge Discovery Center
and each meeting features some
aspect of paleontology. We have
fun activities for the children to
learn about fossils and ancient life.
If your child or grandchild is
interested in joining the PaleoZone,
please contact Dennis at
gertenbach1@gmail.com for more
information. –Dennis Gertenbach
Paper nautiloid models by Alex and Gabe
WIPS Members: We are looking for adults and older teens to help with the PaleoZone program. If you have a
paleontological specialty, consider joining us at one of our monthly meetings to teach the kids about your specialty.
And, we especially need helpers that can come to our monthly meetings on a regular basis. We also need helpers at
every level of fossil expertise at our meetings. Most important are adults and older teens who like working with kids.
The children in the PaleoZone will enjoy the time you spend with them. They love fossils and learning new things.
Contact Dennis for more information about helping with this program.

TRILOBITE
TALES
VOLUME 38, NUMBER 5
MAY 2020
In This Issue
2020 GRANT & SCHOLARSHIP
AWARDEES . . . . . . . . . . . . . . 6
EPONYMOUS EPIGRAMS:
LUTEMYS WARRENI . . . . . . . . . . 16
INVERTEBRATE OF THE MONTH:
CRINOID STEMS . . . . . . . . . . . 19
WHAT WIPS MEANS TO ME
SECOND IN A SERIES . . . . . . . . 21
FINAL (?) IDENTIFICATION OF THE
FALSE EDESTUS . . . . . . . . . . . 23
FROM THE PALEOZONE:
NAUTILOIDS . . . . . . . . . . . . . 27
DEPARTMENTS & COLUMNS
President’s Message . . . . . . . . . 2
Announcements . . . . . . . . . . . . . 3
Denver Show News . . . . . . . . . . 9
Field Trips 2020 . . . . . . . . . . . . 12
Member Profile: JP Cavigelli . . . 14
EVENTS
Science Events Calendar . . . . . 7
WIPS Events this Month . . . . . 31
FOR YOUNGER MEMBERS
PaleoZone . . . . . . . . . . . . . . . . 26
Stegosaurus, the Colorado State Fossil,
Art © Shannon S. Yeager
Ghost Preservation, Drywall Eyeballs,
and Bees: Incredible fossil preservation
from America’s high plains
Virtual Monthly Meeting & Program
Monday, May 4, 2020, 6:30-9:30 p.m.
Speaker: James Hagadorn
Join the meeting and hear the lecture online!
Due to stay-at-home/safe-at-home orders, the next WIPS meeting
will be held virtually. You can attend using your computer, tablet
or smartphone. You can find a link to join the meeting in the
Member Services area of our website, www.westernpaleo.org. The
link and meeting details will also be emailed to members, so
watch your inboxes!
– More details about the May program on page 3

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and displaying fossils; encouraging
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conduct in the exploration for and
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From the President
Here we are at the beginning of May and summer is
just around the corner. It seems like time is flying
by in Colorado as we have all been staying at home,
with similar restrictions in other states in place.
We’re now heading into the safer-at-home phase
where non-critical businesses are allowed to
gradually open and hopefully more widespread
testing will become available so we can begin to get
back to normal again soon. I sincerely hope that
everyone stays healthy through this pandemic and my heart goes out to
everyone who is isolated from their loved ones that remain at higher risk.
Hang in there and remember that we’re all in this together, or
#AloneTogether to be more specific.
Our first virtual general meeting was held on April 6th and judging from
the feedback I received, it went very well. We had a max participation of
about 60 people, which is similar in size to our in-person general
meeting attendance but without all the great snacks and fossils present.
We had an extraordinary talk from Lou Taylor on the topic of “Fossils We
Seldom Hear About” and lots of great questions and discussion afterward.
Our May general meeting is scheduled for Monday May 4th at 6:30 p.m.
MT with speaker James Hagadorn, Curator of Geology at DMNS on the
topic of “Incredible Fossil Preservation from America’s High Plains,” and
we will again be conducting the meeting virtually. Look for an email
invite over the weekend with links to join the meeting. You can also
check the membership section of the WIPS website for links to join by
computer or phone. The virtual experience is certainly better when you
can see the presentation rather than just dialing in, and a webcam will
allow others to see you, but it is not necessary to hear and participate by
voice only. I hope you can join the May general meeting; I’ve invited a
handful of other avocational paleontology societies across the US and
Canada as guests.
We have also been switching our board of director and committee
meetings over to a virtual meeting format and these sessions have gone
well so far too. The Field Trip Committee has been working with each of
the trip leaders and under the guidelines imposed by Colorado and
neighboring states to hopefully still offer a full field trip season this
summer. Keep a close watch on the website and elsewhere here in
Trilobite Tales because some of the field trip dates are having to change.
The Science Committee has been continuing their work on fossil
disposition and we can expect to see their reports soon, beginning with
important policies concerning federal and state law changes. The Denver
Gem & Mineral Show Committee has been continuing their work to
support a show in September this year but whether we have the show
will certainly depend on how state and local guidelines continue to
unfold. The Symposium Committee has been discussing the possibility of
postponing the 2021 WIPS Founders Symposium to 2022, but again this
will have to depend on how state and local guidelines continue to unfold.
2 TRILOBITE TALES | MAY 2020
Dave Fangrow
– Continued on next page
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