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Journal of Paleontology 91(3):369–392 Type species.—Clonophycus elegans Oehler, 1977.
Clonophycus sp. indet. Figure 9.5–9.8
Description.—Spherical coenobium with or without a common envelope. Coenobiums range from 30–57.5 μm in diameter (N = 12) and are composed of tens to hundreds of spherical cell units. Cell units 2.5–12.5 μm in diameter.
Remarks.—These specimens are morphologically comparable to Clonophycus, which has been reported from the Proterozoic Balbirini Dolomite, Australia (Oehler, 1978).
Genus Xiaohongyuia new genus Shi and Feng
Type species.—Xiaohongyuia sinica new genus new species Shi and Feng.
Diagnosis.—An initial vesicle bearing a variable number of irregularly distributed outgrowths. It is characterized for its variable morphology, including but not limited to spherical, binary, lageniform, calabash and chain-like. Irregular-shaped individuals are composed of incomplete spherical parts in var- ious directions.
Etymology.—With reference to their occurrence in Xiaohongyu Valley.
Occurrence.—Fossiliferous bed located ~15m from the top of the third member of the Dahongyu Formation, in the Xiao- hongyu Valley in Jixian area, Tianjin, north China.
Remarks.—Ordinary cells of Xiaohongyuia Shi and Feng n. gen. are mostly spherical. Irregular-shaped individuals are a minority and are composed of incomplete spherical parts in different directions. Cross-walls between every spherical part have been observed in many irregular-shaped specimens. These cross-walls partition the whole organism into two unequal vesicles; or into gourd-, lageniform-, dumbbell-, calabash- and chain-shaped organisms. According to their variable morphol- ogy, X. sinica Shi and Feng n. sp. could undergo active vege- tative reproduction. They have a tendency to develop outgrowths from the initial vesicle, sometimes to the extent of forming secondary vesicles.
Xiaohongyuia sinica new species Shi and Feng Figure 12
Holotype.—The microfossil illustrated in Figure 12.9 is hereby designated as holotype for this species. The holotype specimen is found in Slide 2012JXD4, Dahongyu Formation, Jixian section, Tianjin, China.
Diagnosis.—Outgrowths grown in two perpendicular directions.
Description.—Irregular-shaped organisms. Outgrowths grew in two perpendicular directions. They are, but not limited to,
binary, lageniform, calabash, and chain-like morphologies. Single cells are in the range 15.5–45 μm in diameter (mean = 29 μm; N = 46).
Etymology.—With reference to their occurrence in China. Group Acritarcha Evitt, 1963
Genus Pterospermopsimorpha (Timofeev,1966), emend. Mikhailova and Jankauskas in Jankauskas et al., 1989
Type species.—Pterospermopsimorpha pileiformis Timofeev, 1966.
Pterospermopsimorpha sp. indet. Figure 9.14
Description.—Solitary spherical microfossils with a large, spherical dark inclusion. Wall is thin and transparent. Cells are 38.5–126.5 μm in diameter (mean = 72.2 μm, n = 15). Inclu- sions are 23.8–97.2 μmin diameter (mean = 47.5 μm, N = 15).
Remarks.—We agree with Jankauskas et al. (1989) and include all smooth-surfaced spheres with large spherical inclusions (usually bigger than two-thirds cell diameter) from the new microbiota into Pterospermopsimorpha. According to micro- fossil records, Pterospermopsimorpha emerged as early as late Paleoproterozoic (Yan, 1985), but were more abundant in the late Proterozoic.
Genus Dictyosphaera Xing and Liu, 1973
Type species.—Dictyosphaera macroreticulta Xing and Liu, 1973.
Dictyosphaera macroreticulata Xing and Liu, 1973 Figure 10.10, 10.11
1973 Dictyosphaera macroreticulata Xing and Liu, p. 22, pl. 1, figs. 16, 17.
2015 Dictyosphaeramacroreticulata Xing and Liu; Agić et al., p. 32, fig. 2.1–2.9.
For additional synonymy see Agić et al., 2015.
Holotype.—Specimen illustrated in pl. 1, fig. 16 (Xing and Liu, 1973).
Description.—Spherical cells with reticulate sculptures on their surface. Cells are 40.5–49.5 μm in diameter (mean = 45 μm; N = 2). Cell wall is single-layered, thick, and translucent.
Remarks.—Dictyosphaera was first described from the Chuan- linggou Formation of the Jixian section (Xing and Liu, 1973), and subsequently reported from several localities in Mesopro- terozoic strata in North China (Hu and Fu, 1982; Yan and Liu,1993; Xiao et al., 1997; Li et al., 2012; Agić et al., 2015). The new specimens are similar to the “Dictyosphaera sinica” reported from the Chuanglinggou Formation, Jixian section (Xing and Liu, 1973; Fig. 1.18, 1.19). Their reticulate sculptures
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