Flat nematophyte - Details and
A recently found nematophyte resembling Nematophyton
taiti found in the Rhynie chert about a hundred
years ago  shows a few details from which a tentative reconstruction
can be derived. (See also Rhynie
Chert News 35.)
Since the nematophytes have not
yet been placed on a branch of the phylogenetic tree but go under the
haunting term Enigmatic Organisms , any new detail will be of
As explained before, nematophytes are made up
of tube-like filaments of two or more types, probably embedded in
which keeps them together and keeps floating debris out.
specimen shows three types of tissues in a wider sense (Fig.1). There
is an inner stratum with big tubes of about 20Ám diameter and probably
much smaller tubes, not seen here, in between. This inner stratum is
surrounded by an envelope consisting of randomly oriented smaller tubes
which mainly appear as dark sections indicating
diameters of about 10Ám. Embedded in the envelope layer there
are pockets of aligned tubes in a more or less fan-shaped
arrangement, diverging towards the surface (Fig.2). Remarkable are the
chains of dark dots apparently
generated in some of the tubes (Fig.1), with superficial resemblance to
ascispores of the ascomycetes.
Fig.1: Nematophyte from Rhynie chert,
half vertical section, middle stratum with big tubes below, envelope
layer above, with pocket of aligned tubes, rows of dark dots therein.
Width of the image 1mm.
Fig.2: Three adjacent pockets of tubes aligned in a fan-like way in the
envelope layer of the nematophyte
specimen presented here.
Fig.3 (below): Tentative reconstruction based
on observed details of the flat nematophyte specimen
recently found in the Rhynie chert. Width about 3cm.
The above reconstruction is based on a specimen which is not
preserved as a whole but as several fragments (in one piece of chert)
which seemed to have
belonged to a patch with a diameter of about 3.5cm. The characteristic
"branch knots" seen among the big tubes in other
representing other species seem to be less conspicuous here, which may
or may not be merely
The flat shape of this specimen supports the assumption that Nematothallus*,
is found as coalified patches , had not been bulky
Nematophyton in  but flat before
compression. This conclusion had been offered at
the EPPC 2010 .
Although of no relevance to the present reconstruction, it is worth
mentioning that the tube sizes of several
nematophyte specimens from the Rhynie chert differ considerably. The
diameter of the aligned tubes is about 10Ám in
this specimen, about
20Ám in Pachytheca, and about 60Ám in the
specimen shown in Rhynie
Chert News 30. The
wound tubes of two own Nematoplexus
specimens are twice as big as those of the type specimen.
It can be hoped that observations like the present
ones will gradually contribute
to a better understanding of the nematophytes so that they
eventually don't have to carry the epithet "Enigmatic Organisms" any more.
*(Sorry, Nematothallus and Nematophyton
had been confused here in the previous version of this text.)
Kidston, W.H. Lang: On Old Red Sandstone plants showing
structure ..., Part V,
Soc. Edinburgh 52 (1921), 855-902.
 T.N. Taylor,
E.L.Taylor, M. Krings: Paleobotany, Elsevier 2009.
 P. K. Strother:
Clarification of the genus Nematothallus,
J. Paleont. 67 (1993),
Weiss: Enigmatic Organisms - Insights
derived from new finds, Poster presentation, EPPC Budapest 2010.