Gilboa - Fossil Ecosystems of North America: A Guide to the Sites and their Extraordinary Biotas - page 93

Progymnosperms
These are the most advanced trees found in
the New York localities described here. As
the name suggests, their morphology is part-
way between the spore-bearing plants
and the more advanced seed-bearing
gymnosperms: progymnosperms bear
sporangia and have leafy branches on large
trunks whose wood is gymnospermous in
nature. The foliage of Aneurophyton ,
originally described by Goldring
(1924) from the stump localities, is
progymnospermous, as is Rellimia , another
common progymnosperm from Brown
Mountain. Their axes show more complex
branching than the simple dichotomous
patterns seen in more primitive vascular
plants. Both of these genera may well
have been herbaceous rather than
trees. The well-known progymnosperm
Archaeopteris occurs in abundance at
South Mountain ( 93 ). It was an arborescent
progymnosperm with leafy branches on
large trunks similar to modern trees.

preserved in the New York State Museum.
Presumably, this trunk floated out from
the Catskill delta until it became
waterlogged and sank into the deep sea to
be covered by dark mud.
Herbaceous lycopods include
Gilboaphyton goldringiae , described by
Arnold (1937), Protolepidodendron
gilboense , a Grierson and Banks (1963)
species, Haskinsia and Leclercqia
complexa , the anatomy of which was
uncovered by the painstaking work of
Banks, Bonamo, and Grierson referred to
above (Banks et al ., 1972). Gilboaphyton ,
the leaves of which have two lateral teeth,
has since been found in the Devonian of
Venezuela (Berry and Edwards, 1997).
The spores of Leclerqia were studied by
Richardson et al . (1993). Spores can be
important for establishing stratigraphy
where other zonal indicators (e.g. marine
invertebrates) are absent. However, study
of spores within sporangia are necessary to
identify correctly to which plant the
abundant dispersed spores in the rock
belong. Leclercqia has hook-like, recurved
leaves with four lateral branches and it is
this characteristic which produced the
tangled masses of the plant, found in the
rocks at Brown Mountain, which acted as a
mesh to entrap the animal remains which
make the locality an important Lagerstätte
for Devonian land animals.

Cladoxylopsida
Details of the internal anatomy of this
group of Devonian plants are confusing
regarding their placement among other
plant groups. They show the most
complex vascular strand patterns of all
the Devonian plant groups, and are also
the commonest of the arborescent forms.

93

93 Foliage of the
progymnosperm Archaeopteris
at South Mountain. Lens cap
diameter 6 cm 2.4 in.