四川早泥盆世植物群的研究

本文首次系统地记述了四川下泥盆统平驿铺组的植物化石，共计9属13种，其中包括一个新属 和三个新种。它们分属于苔藓植物(?)和早期维管植物的四大类(Rhyoiophytina、Zosterophyllo-phytina， Trimerophytina和Lycophytina)。根据植物组合的面貌，还讨论了平驿铺组的地质时代相当于欧洲的西根期(Siegenian)，并可能包括部分吉丁期(Gedinnian)和最早的埃姆斯期(Emsian)。

Studies on Early Devonian Flora of Sichuan

An Early Devonian flora from the Pingyiqu Formation of northern Sichuan is described. It contains 13 species in 9 genera. They are Eogaspesiea gracilis, Uskiella sp., Zosterophyllum myretonianum, Z.yunnanicum, Z.sichuanense sp.nov., Oricilla unilateralis sp.nov., Hicklingia cf.edwardii, Psilophyton sp., Drepanophycus spinaetormis, D.spinosus, D.sp., Leclercqia complexa, and Sciadocillus cuneifidus gen.et sp.nov. The geologic range of the flora is inferred to be Siegenian (probably Upper Gedinnian-Siegenian).      Sciadocillus gen.nov. (Marchantiales?)      Diagnosis: Thalli flattened, composed of a central disc-like structure and radiating wedge-shaped unbranched lobes. Sporangium-like reproductive organs round to elliptic, at- tached to the upper surface and along the edges of the lobes. Spores trilete.      Type species: Sciadocillus cuneifidus      Sciadocillus cuneifidus sp.nov.      Thallus, 4.2mm in diameter, consists of a central disc-like structure, about 1.0mm in di- ameter, bearing 14 unbranched lobes. Lobes wedge-shaped, 1.5-1.75mm long , 0.75- 0.83mm wide at the apex and 0.25mm at the base. Sporangium-like reproductive organs round to elliptic, 0.45-0.50mm long and about 0.4mm wide, without stalks. Spores, spheroidal to subspheroidal, 20-40μm in diameter, trilete, exine smooth, sometimes folded.      Holotype: Plate 7:53, 54 (counterpart).      Locality: Approximately 800m, in northwest Yanmenba Village, Jiangyou, Sichuan.      Horizon: Lower part of Pingyipu Formation (Upper Gedinnian-Siegenian).      Zosterophyllum Penhallow (1892) (Zosterophyllaceae)      Zosterophyllum sichuanense sp.nov.     Plant with smooth axes at least 57mm long, 1.6-2.0mm wide, branching unknown. Fertile axes terminate in lax spikes, about 6.5mm wide; spikes with spirally arranged sporangia, three to four gyres. Sporangia borne on stalks, 2.7-3.9mm long and 0.54- 0.81mm wide; stalks obliquely inserted on axis, gentely cured upwards, in profile often C-shaped with adaxial margins of sporangia; stalk contain vascular strand. Sporangia Fan-shaped, often folded in half and margins facing axis, almost triangular in side view, sometimes obovate in abaxial view; dehiscense not observed.     Holotype: Plate 2:11.     Paratype: Plate 2:10, 14.      Locality: approximately 800m, northwest Yanmenba Village, Jiangyou, Sichuan.      Horizon: Pingyipu Formation (Siegenian).      Oricilla Gensel (1982) (Zosterophyllaceae)      Oricilla unilateralis sp.nov.      Plants erect. Naked axes at least 76mm long, 1.6-3.2mm wide, branching dichotomous with branching angles 30-60°in fertile regions. Sporangia borne laterally in one row on branches, located above bifurcation, oriented to inside of axis. Stalks not observed. Sporangia probably attached by an extremely short stalk to axis at right angle. Sporangia reniform to ellitical, 2.8-4.0mm wide (X=3.3mm), 2.0-2.5mm high (X =2.3mm) , composed of two equal valves, dehiscent along distal margin. Spores subcircular, trilete, 48-58μm, in diameter, smooth, with dark area at juncture of trilete rays. Surface covered with tapetal residue.      Holotype: Plate 4: 28.      Paratype: Plate 4: 30-32.      Locality: Approximately 800 m northwest Yanmenba Village, Jiangyou, Sichuan.     Horizon: Pingyipu Formation (Siegenian).