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Amurodendron pilosum
Amurodendron pilosum A.B. Sokolova, Zavial., M.G. Moiseeva, Kodrul Paleontol. J., 57: 1190. Dec 2023
- Name
- Amurodendron pilosum
- Rank
- Species
- Generic Name
- [Genus] Amurodendron
- Authors (Pub.)
- Sokolova A. B.
Zavialova N. E.
Moiseeva M. G.
Kodrul T. M.
- Publication
- The new genus Amurodendron (Cupressaceae s.l.) from the Paleocene Boguchan flora of the Amur Region (Russian Far East) [2023/12]
- Journal
- Paleontological Journal
- Volume
- 57
- Page number
- 1190
- Year
- 2023
- Fossil Status
- leafy twigs (with male cones)
- Stratigraphy
- Paleocene
- Strat. comment
- Middle Tsagayan subformation of Tsagayan Formation
- Location
- Arkhara-Boguchan coal field (49°18.780′ N, 130°12.808′ E), Amur Region, Russian Federation
- Paleoregion
- Eurasia (Far East)
Data for Holotypus
- Repository Number
- GIN 4867, specimen no. AB1–492
- Num
- Pl. 11, Fig. 7; Pl. 13, Figs. 1–5; Pl. 14, Figs. 1–5; Pl. 15, Figs. 1–6; Pl. 16, Figs. 1–4, 6, 10; Pl. 17, Figs. 1–4; Pl. 18, Figs. 1–4; Figs. 2c, 2d
- Pub.
- The new genus Amurodendron (Cupressaceae s.l.) from the Paleocene Boguchan flora of the Amur Region (Russian Far East) [2023/12]
- Diagnosis
- Shoots terminal. Leaves polymorphic:
from scale-like to linear-lanceolate. Shoot axis
0.7–1.0 mm. Linear-lanceolate leaves 6.0–16.0 ×
1.0–1.5 mm, decrease from base to apex of shoot; helically
arranged, curving at base to orient in roughly one
plane; angle of leaf deviation up to 80°; long-decurrent
bases leave oblique to parallel lines on shoot axis.
Numerous hair-like teeth 20–200 × 10–20 μm locate
along leaf margin and on shoot axis. Scale-like leaves
helically arranged, rhomboid; 1.0–5.0 × 1.0–2.5 mm;
free part of leaves triangular. Scale-like leaves locate at
bases of shoots and on axes bearing pollen cones. All
leaves amphistomatic; stomata monocyclic or incompletely
amphicyclic; anticlinal walls of epidermal cells
straight. In linear leaves two stomatal bands consist of
one to six stomata per width on abaxial surface and up
to three to four on adaxial surface; predominantly longitudinally
oriented stomata form discontinuous rows;
epidermal cells of non-stomatal zones arrange in regular
rows parallel to leaf margins; their length/width
ratio about 11/1. In scale-like leaves stomatal bands
with two to four stomata per width in middle part of leaf, consist of irregularly oriented stomata. Pollen
cones ellipsoidal, terminal or lateral, 5.5–7.5 × 3.0–
3.5 mm; lateral cones arrange alternately or subopposite;
each lateral cone supported by thin saber-like leaf
up to 5 mm long, curved towards axis. Each cone consists
of 10–14 rhomboid microsporophylls helically to
decussately arranged. Pollen grains 23–27 μm in size,
rounded, with small distal papilla. The ectexine with
tectum of fused granules, infratectum of smaller
loosely arranged granules and thin foot layer, and the
endexine with six lamellae.