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Minostrobus chaohuensis
Minostrobus chaohuensis Y. Wang Bot. J. Linn. Soc., 136(4): 444. 28 Jul 2001
- Name
- Minostrobus chaohuensis
- Rank
- Species
- Generic Name
- [Genus] Minostrobus
- Authors (Pub.)
- Wang Y.
- Publication
- A new lycopsid megaspore cone from the Upper Devonian of Chaohu, China [2001/7]
- Journal
- Botanical Journal of the Linnean Society
- Volume
- 136
- Issue
- 4
- Page number
- 444
- Year
- 2001
- Fossil Status
- strobili
- Stratigraphy
- Famennian
- Strat. comment
- Wutung Formation
- Location
- small quarry, south side of Beisham hill, Sizikou, 3 km north of Chaohu City, Anhui Province, China.
- Paleoregion
- Cathaysia (South)
Data for Holotypus
- Repository
- Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China
- Repository Number
- PB 18751
- Diagnosis
- Cone at least 12cm long. Cone axis, c. 1.2 mm wide. Sporophyll cushion, circular in outline, c. 0.3-0.4 mm in diameter. Sporophylls inserted on the cone axis at an angle of 20-30", and recurved distally to an angle of 80-90". Six sporophylls of each gyre arranged on tight spiral whorls at the angle of 3040" clockwise, vertical distance, c. 1.5 mm. Stalk of sporophyllO. 5-0.7 mm wide andless than 0.5 mm long. Distal part of sporophyll, 6-8 mm long. Lamina flattened and circular in profile c. 1.5-2.2 mm wide, with a pointed apex and smooth margins. One vein reaching the apex of sporophyll. Sporangium spherical or sphericalelliptical in profile, about 2-3 mm in diameter, without pedicel. Wall of sporangium smooth, about 0.2-0.4 mm thick. Megaspore more or less circular amb, nearly pearshaped in equatorial view, about 600-800 pm in equatorial width and 800-1300pm in total height. Spore body about 500-650pm high. Gula about 450- 500 pm x 100-150 pm height x basal width. Trilete ridges, tongue shaped, with a round apex, with three radial ridges at the lower part. Surface of gula smooth, rest of spore surface with scattered biform ornamentation. Base of biform ornamentation, tubercles bulbiferous in shape, about 10-18 pm in diameter and 10-20 pminheight. Apical spines, about 6-8 pminbasal diameter, and 18-25- long, with sharply pointed ends. Cone axis with primary xylem strand about 250 pm in diameter, exarch. 12 ridges of protoxylem around the metaxylem core. Annular protoxylem tracheids circular in profile in cross section, c. 5-10 pm wide. Scalariform and reticulate metaxylem tracheids polygonal in cross section, c. 15-35 pm wide, Williamson’s striations in the aperture. A vascular strand at sporophyll base, about 45-50 um in diameter, mesarch. Cortical cells, rectangular in outline, c. 70-90 pm long and 25-30 p wide, cell wall less than 1.0 pm thick.
