Fistuliramus xianzaensis Liu and Wang, 1987

Ernst, Andrej, 2016, Bryozoan fauna from the Permian (Artinskian-Kungurian) Zhongba Formation of southwestern Tibet, Palaeontologia Electronica (1946) 51 (9), pp. 1-59 : 9-11

Fistuliramus xianzaensis Liu and Wang, 1987

Figures 4.8 , 5.1-3 ; Table 5

1987 Fistuliramus xianzaensis Liu and Wang , p. 5, pl. 2, figs. 2a-c, pl. 3, fig. 1a-c.

Material. SMF 23.036- SMF 23.050.

Description. Branched colonies 5.9–8.3 mm in diameter, with 3.3–5.1 mm wide endozones and 1.1–2.3 mm wide exozones. Autozooecia long in endozones, bending at low angles in exozones. Autozooecial diaphragms few, thin, planar, or concave, concentrated in the transition zone between endozone and exozone. Autozooecial apertures rounded. Lunaria well-developed, horseshoe-shaped, originating in endozone, consisting of granular material. Vesicles abundant both in endozone and exozone, moderately large, box-like, polygonal in tangential section, having flattened roofs, separating autozooecia in 1–3 rows and 10– 13 surrounding each autozooecial aperture; in endozone usually twice as high as those in exozone. Autozooecial walls granular prismatic, 0.005 –0.010 mm thick. Maculae not observed. Granular skeleton on colony surface poorly developed.

Remarks. Fistuliramus xianzaensis Liu and Wang, 1987 is similar to F. bifidus Yang and Xia, 1975 from the Lower Permian of China, but differs by wider branches (5.9–8.3 mm vs. 3.2–5.6 mm in F. bifidus ) and by larger and more abundant vesicles (average vesicle diameter 0.12 mm vs. 0.09 mm in F. bifidus ). Fistuliramus xianzaensis differs from F. elevatus Liu and Wang, 1987 from the Lower Permian of China in larger autozooecial apertures (average aperture width 0.29 mm vs. 0.19 mm in F. elevatus ).

Occurrence. Xiala Formation,?Middle Permian; Xainza, southwestern Tibet. Zhongba Formation, Permian (upper Cisuralian –Guadalupian); Zhongba area of southwestern Tibet .

Figures

FIGURE 4. Thin section photographs of Fistulipora sakagamii n. sp., holotype SMF 23.028 (1 and 2); Dybowskiella hupehensiformis n. sp., holotype SMF 23.030 and paratype SMF 23.032 (3–7); and Fistuliramus xianzaensis Liu and Wang, 1987, SMF 23.037 (8). 1, 2, 5–7, tangential section showing autozooecial apertures and vesicles; 3 and 4, longitudinal section showing autozooecial chambers and vesicular skeleton; and 8, branch transverse section.

FIGURE 5. Thin section photographs of Fistuliramus xianzaensis Liu and Wang, 1987, SMF 23.042 (1) and SMF 23.038 (2 and 3); and Eridopora uncata Yang and Lu, 1983, SMF 23.052 (4 and 6) and SMF 23.051 (5). 1, longitudinal section; and 2–6, tangential section showing autozooecial apertures and vesicles.