1852 Thinnfeldia speciosa ETTINGSHAUSEN, p. 4, Pl. 1, Fig.
8.
1855 Pachypteris speciosa ANDRAE, p. 44.
1997 Thinnfeldia speciosa POPA, p. 82-84, Pl. 1, Figs. 1-2,
Pl. 2, Figs. 1-4, Text-figs. 1-4, 6.
2000 Pachypteris speciosa POPA, p. 128-132, Text-fig. IV.
37, 41, 43-44, 46-53, Pl. 52, Figs. 1, 3-6, Pls. 53-55, Pl. 109, Figs.
1-3.
2003 Komlopteris speciosa CLEAL and REES, p. 751-752, Pl.
13, Fig. 3, Pl. 15, Fig. 1.
Pteridospermopsida/Corystospermales
Short description
Pinnate leaf, with elongated, opposed to sub-opposed pinnules.
Pinnules with entire margins, slightly acute apex, alethopterid venation,
with a clear midrib and secondary veins simple or rarely divided dichotomously,
at angles of about 30° with the midrib. Leaves hypostomatic, with
thick cuticles, with stomata confined to areas between the secondary
veins. The stomatal apparatus has thin guard cells, 4-6 subsidiary cells,
trapezoidal or elongated, organized in bowl-shaped collars.
Discussion
Pachypteris speciosa is a very interesting Corystospermal species
for its anatomy, taxonomy and ecology. It was defined as a Thinnfeldia
species by Ettingshausen (1852) from Steierdorf-Anina, the type locality
of this denomination. Popa (1997), tried to keep the genus Thinnfeldia
separated from Pachypteris and Komlopteris, at least
for the species T. speciosa, on vegetative material collected
from the same locality. However, this taxonomical position is impossible,
as the type species of genus Thinnfeldia ETTINGSHAUSEN 1852,
T. rhomboidalis, is a Pachypteris (BRONGNIART) DOLUDENKO
1971 species, so Thinnfeldia is a junior synonym of Pachypteris,
as Doludenko (1971, 1974) demonstrated. P. speciosa has a special
place within the genus Pachypteris, as Popa (2000) emphasized,
with affinities for both Pachypteris and Komlopteris.
Cleal and Rees (2003), discussing about interesting material found in
UK, considered this species as a Komlopteris species, based
on morphological considerations. Popa (2000) described in detail the
species, with its related vegetative and reproductive structures, keeping
it assigned to Pachypteris.
Occurrence
Anina, mainly within the Ponor SSSI, where it is exceptionally preserved
and abundant.
Phytostratigraphy
This species is Hettangian in age, belonging to the Thaumatopteris
brauniana assemblage zone in the South Carpathians.
Paleoecology
Pachypteris speciosa is a marsh dweller, sometimes occurring
on marsh edges. It is a coal generator, competing sometimes for the
wet habitats with Cheirolepidiaceous conifers with foliage such as Pagiophyllum
sp. or Incertae sedis conifers such as Podozamites paucinervis.
This competition (Popa, 1997) was reflected in the coal genesis of a
local Hettangian coal seam in Ponor SSSI.
Material
The material is exceptionally preserved in Anina, mainly in the Ponor
SSSI, where all organs of this plant were collected.
References
Andrae, C., 1855. Beitrage zur kenntniss der fossilen Flora Siebenburgens
und des Banates. Abhandlungen der K. K. geologischen Reichsanstalt,
III(4): 1-48.
Cleal, C.J. and Rees, P.M., 2003. The Middle Jurassic flora from
Stonesfield, Oxfordshire, UK. Palaeontology, 46(4): 739-801.
Doludenko, M.P., 1971. Thinnfeldia - mladsii sinonim Pachypteris.
Paleont. Journ., 2: 99-104.
Doludenko, M.P., 1974. On the relation of the genera Pachyperis,
Thinnfeldia and Cycadopteris, Symposium on Morphological
and Stratigraphical Paleobotany, Lucknow, pp. 8-16.
Ettingshausen, C., 1852. Begrundung einiger neuen oder nicht genau
bekannten Arten der Lias- und Oolithflora. Abhandlungen der K. K.
geologischen Reichsanstalt, 1(3 (3)): 1-10.
Popa, M.E., 1997. Corystospermal pteridosperms in the Liassic continental
deposits of Romania. Acta Palaeontologica Romaniae(1): 81-87.
Popa, M.E., 2000. Early Jurassic land flora of the Getic Nappe, University
of Bucharest, Bucharest, PhD thesis, 258 pp.