Help with fossil ID

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Glenn Simonelli - 20 Dec 2004 19:31 GMT

Hi.
Does anyone have any idea what this might be? It was found in
Pennsylvanian era siltstone in what was probably a brackish,
tidally-influenced mudflat.

http://mypage.iu.edu/~gsimonel/Temp/Picture%20002_small.jpg

The black and white lines are each 1 mm, so the objects are around 4-5
mm wide and less than 1 cm long. It looks like it might be something
coiled, but the rock is only ~6mm thick and there is no hint of the
object on the underside. Thanks for any suggestions that you can offer.

Glenn Simonelli
http://mypage.iu.edu/~gsimonel

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Henry Bartlett - 20 Dec 2004 20:56 GMT

> Hi.
> Does anyone have any idea what this might be? It was found in
> Pennsylvanian era siltstone in what was probably a brackish,
> tidally-influenced mudflat.

I am not familiar with Pennsylvanian plant fossils but this looks to
me to be a fragment of a fern frond and, if it is from the end of a
young frond, then, yes, it may be coiled.

The "objects" are pinnules (the tiny leaflets you often see on fern
fronds)

--
Henry Bartlett

> Hi.
> Does anyone have any idea what this might be? It was found in
[quoted text clipped - 10 lines]
> Glenn Simonelli
> http://mypage.iu.edu/~gsimonel

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Ken Shaw - 20 Dec 2004 21:55 GMT

> Hi.
> Does anyone have any idea what this might be? It was found in
[quoted text clipped - 10 lines]
> Glenn Simonelli
> http://mypage.iu.edu/~gsimonel

Looks like a fossil plant imprint. Probably fern tips but it's hard to
tell from the photo.

Ken

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mel turner - 21 Dec 2004 04:20 GMT

> Hi.
> Does anyone have any idea what this might be? It was found in
[quoted text clipped - 7 lines]
> coiled, but the rock is only ~6mm thick and there is no hint of the
> object on the underside. Thanks for any suggestions that you can offer.

It looks to be a series of leaflet impressions of a fern-like leaf.
The rachis would be broken away about where the groove is just
above the scale bar.

["Fern-like", because it is likely to actually be from an early
seed-bearing plant, not a true fern. Many such pteridosperms or
"seed ferns" are well-known from Carboniferous deposits,
and various named genera and species are distinguished based
mainly on details of leaflet shapes and venation patterns.

The form-genus "_Neuropteris_" seems likely to apply here, but that
ID depends in part on the basal parts of the leaflets that are not
very clearly seen here.

http://www.uni-muenster.de/GeoPalaeontologie/Palaeo/Palbot/seite9.html
http://www.xs4all.nl/~steurh/englod/eneurprm.html
http://www.soton.ac.uk/~bam2/col-index/fossi-lindex/plants/carbonif/pages/Neuro-
nd.htm
http://paleontologia.co.uk/paleopag/practices/paleob_irecfrpal_tema3.htm
[an illustrated identification key to fossil form-genera, in Spanish]
http://www.xs4all.nl/~steurh/engvar/etabel.html [a key, in English]
http://www.geocraft.com/WVFossils/TreeFerns.html
http://www.clearlight.com/~mhieb/WVFossils/TreeFerns2.html
http://www.google.com/images?as_q=neuropteris&svnum=10&hl=en

cheers

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Natural Science Forum / Biology / Paleontology / December 2004

Help with fossil ID