Polypora consanguinea Bassler, 1929

Ernst, Andrej, 2016, Bryozoan fauna from the Permian (Artinskian-Kungurian) Zhongba Formation of southwestern Tibet, Palaeontologia Electronica (1946) 51 (9), pp. 1-59 : 40

Polypora consanguinea Bassler, 1929

Figure 18.1-4 ; Table 24

1929 Polypora consanguinea Bassler , p. 79, pl. 19, figs. 5-9.

Material. SMF 23.182.

Exterior description. Reticulate colonies composed of moderately wide branches jointed by moderately wide dissepiments. Autozooecia arranged in 4–5 alternating rows on branches. Autozooecial apertures rounded to oval, 4–10 spaced per length of fenestrule. Fenestrules long, oval, narrow. Node regularly spaced between subsequent autozooecial apertures, 0.03–0.04 mm in diameter. Reverse colony surface smooth.

Interior description. Autozooecial chambers moderately long, generally rhombic to roughly hexagonal in the mid tangential section. Hemisepta absent. External laminated skeleton well-developed, traversed by abundant small microacanthostyles. Heteromorphs not observed.

Remarks. Polypora consanguinea Bassler, 1929 is similar to P. russiensis Schulga-Nesterenko 1941 from the Lower Permian of Russia, but differs from it in having wider branches (branch width 1.08– 1.45 mm vs. 0.52–0.88 mm in P. russiensis ) and wider fenestrules (fenestrule width 1.08–1.40 mm vs. 0.45–0.70 mm in P. russiensis ). Polypora consanguinea differs from P. multiporifera Crockford, 1944 from the Lower Permian of Western Australia in having wider branches (branch width 1.08–1.45 mm vs. 0.70–1.10 in P. multiporifera ) as well as wider and shorter fenestrules (fenestrule width 1.08–1.40 mm vs. 0.65–1.10 mm in P. multiporifera ; fenestrule length 2.00– 2.10 mm vs. 2.1–2.45 mm in P. multiporifera ). Polypora consanguinea Bassler, 1929 has been reported from the Lower Permian (Kungurian) of northern Russia ( Morozova, 1981, p. 85), however, this species possesses hemisepta.

Occurrence. Permian (Sakmarian–Artinskian); Indonesia, Timor. Zhongba Formation, Permian (upper Cisuralian–Guadalupian); Zhongba area of southwestern Tibet.

Figures

FIGURE 18. Thin section photographs of Polypora consanguinea Bassler, 1929, SMF 23.182 (1–4); and Polypora brouweri Bassler, 1929, SMF 23.183 (5–9). 1, oblique section; 2–5, tangential section showing autozooecial apertures, nodes and autozooecial chambers; 6, reverse side of the colony; and 7–9, tangential section showing autozooecial apertures and chambers.