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Knorripteris taylorii
Knorripteris taylorii Galtier, C.J. Harper, R. Rössler, Kustat., M. Krings in M. Krings, C.J. Harper, Cúneo, G.W. Rothwell Transf. Paleobot. 196. 20 Jul 2018
- Name
- Knorripteris taylorii
- Rank
- Species
- Generic Name
- [Genus] Knorripteris
- Authors (Pub.)
- Galtier J.
Harper C. J.
Rössler R.
Kustatscher E.
Krings M.
- Publication
- Enigmatic, structurally preserved stems from the Triassic of Central Europe: a fern or not a fern? [2018/7]
- Authors (Book)
- Krings M.
Harper C. J.
Cúneo N. R.
Rothwell G. W.
- Book
- Transformative Paleobotany
- Page number
- 196
- Year
- 2018
- Fossil Status
- stems
- Stratigraphy
- Ladinian
- Strat. comment
- Precise age unknown. Original label indicates uppermost Muschelkalk or lowermost Keuper
- Location
- Precise locality unknown. Collected east of the city of Schweinfurt (Schonunger Bucht), rom sands along the left bank of the
river Main, Bavaria, Germany
- Paleoregion
- Eurasia (Europe)
Data for Holotypus
- Repository
- Bayerische Staatssammlung für Paläontologie und Geologie, Munich, Germany
- Repository Number
- Specimen pieces and slides SNSB-BSPG
1968 I 97AeE (specimen pieces) and SNSB-BSPG
1968 I (ex 97) 269e273 (thin sections)
Data for Paratypus
- Repository
- Museum für Naturkunde, Chemnitz, Germany
- Repository Number
- Specimen and slides under acquisitions
K4549AeC, K4549-DS1, and K4549-DS2
- Diagnosis
- Stems up to 60 mm in diameter
show acropetal decrease in diameter. Rounded base with
central vascularized scar is suggestive of a zone of attachment
in one specimen 8.5 mm long. Leaf bases are recognizable
as narrow ridges (2 mm wide), helically arranged.
Prominent parenchymatous cortex up to 25 mm thick,
relatively uniform, has no evidence of zonation. Parenchyma
cells are polygonal, often isodiametric, and sometimes
showing vertical alignment. Cells vary in diameter
from 10 to >200 mm; intercellular spaces exceed 100 mm
diameter. Smallest cells (10e20 mm) occur in leaf bases,
around the outgoing leaf traces, and in continuous darker
zone bounding phloem. Discontinuous phloem cylinder
(2 mm thick and 8e16 mm diameter) composed of >10
irregularly shaped strands (each up to 2 mm wide) of thinwalled
cells, generally decayed. Phloem parenchyma of
small cells (10e20 mm diameter) extend around phloem
strands and departing leaf traces, in continuity with innermost
cortex. Central circular xylem zone 5e10 mm in
diameter, containing numerous flattened strands (up to 2.2 mm wide) of scalariform tracheids surrounded by
small-celled parenchyma. Xylem strands, in the continuity
of the leaf trace xylem, extend down to center of stem
where up to three small strands occur in close contact.
There is no evidence of lateral fusion of tracheid bundles,
which are enveloped by parenchyma and associated with
transfusion tissue. Innermost layers of continuous xylem
parenchyma proliferate into cells (20e50 mm diameter and
up to 100 mm long) with spiral thickenings (transfusion
tissue). Accumulations of this tissue are present only in
central “lacunar” xylem zone. Transverse sections of cortex
with up to 70 leaf traces are arranged in sets of five, eight,
or 13 parastichies. Leaf traces are oval (approximately
1 mm radially 0.5 mm), with the same overall dimensions
throughout the cortex. Continuous, multilayered
zone of small parenchyma cells encircles and separates
tracheid xylem bundles from phloem. Departing leaf traces
with xylem bundle are initially flattened, becoming crescent
shaped, abaxially curved with abaxial protoxylem. Xylem
bundle up to 2 mm wide in phloem zone decreases significantly
to <0.5 mm in outer cortex. In contrast, phloem
bundles are initially circular (0.5 mm diameter) but slightly
increase in size distally. Leaf traces are in the middle cortex
frequently with tyloses originating from cells of narrow
parenchyma zone between phloem and xylem, and developing
inside adjacent tracheid strand. Internodes are very
short, approximately 1 mm.
