Upper Ordovician Bryozoans from the Xiazhen Formation of Yushan

Available online at www.sciencedirect.com

ScienceDirect

Palaeoworld 27 (2018) 343–359

Upper Ordovician bryozoans from the Xiazhen Formation of Yushan,

northeastern Jiangxi, East China

a,b a c d a,∗

Min Zhang , Feng-Sheng Xia , Paul D. Taylor , Kun Liang , Jun-Ye Ma

State Key Laboratory of Palaeobiology and Stratigraphy (SKLPS), Nanjing Institute of Geology and Palaeontology (NIGP), Chinese Academy of Sciences (CAS),

Nanjing 210008, China

University of Chinese Academy of Sciences (UCAS), Beijing 100049, China

Department of Earth Sciences, Natural History Museum (NHM), London, SW7 5BD, UK

Key Laboratory of Economic Stratigraphy and Palaeogeography (LESP), Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing

210008, China

Received 1 November 2017; received in revised form 9 January 2018; accepted 19 January 2018

Available online 3 February 2018

Abstract

The bryozoan fauna from the Xiazhen Formation (Katian, Upper Ordovician) of northeast Jiangxi Province, southeast China is reported here.

Seventeen species of bryozoans belonging to ﬁfteen genera and four orders are identiﬁed: Homotrypa yushanensis, Homotrypa sp., Prasopora

yushanensis, Trematopora sp., Monotrypella sp., Rhombotrypa sp., Orbignyella sp., Constellaria jiangxiensis, Constellaria sp., Stictopora nichol-

soni, Trigonodictya parvula, Ptilodictya ensiformis, Stictoporella sp., Pseudopachydictya sp., Nematopora sp., Arthrostylidae sp. indet., and

Chasmatoporidae sp. indet. Four of these genera have been reported previously but nine genera (Trematopora, Monotrypella, Rhombotrypa,

Orbignyella, Trigonodictya, Ptilodictya, Stictoporella, Pseudopachydictya, and Nematopora), one rhabdomesine and one fenestrate are found for

the ﬁrst time in the Late Ordovician strata of South China. Our palaeogeographical analysis suggests that the bryozoan association is typical for

the Katian, which is mostly widespread in Laurentia, Siberia, Baltica and Mediterranean, and displays palaeobiogeographical relationships to the

Laurentia–Siberia Province.

Keywords: Bryozoa; Taxonomy; Palaeobiogeography; Late Ordovician; South China Block

1. Introduction China will contributed greatly to our understanding of the GOBE

(Great Ordovician Biodiversiﬁcation Event) at a global scale

Abundant bryozoans of the Late Ordovician age were (Zhan et al., 2013).

reported from China during the last century (Yang and Hu, 1962; In contrast to the coeval mostly deeper water deposition set-

Yang and Lu, 1962; Yang et al., 1979; Liu, 1980, 1987; Hu, tings in South China in the Late Ordovician (e.g., Rong and

1986a, 1986b; Zheng, 1989; Fan and Hu, 1990). However, little Chen, 1987; Zhan and Jin, 2007), the shallow marine carbonates,

attention has been paid to these bryozoans and little progress especially reefal units or mud mounds of the Xiazhen Formation

has been made with them in recent years, except for the report and the Sanqushan Formation in Jiangshan–Changshan–Yushan

of Chang et al. (2011a, 2011b). For the Late Ordovician bry- (JCY) at the border of Jiangxi and Zhejiang provinces, provided

ozoans from South China, there was only one basic report of a favourable environment for benthic suspension feeding bry-

bryozoans from the Upper Ordovician of South China (Hu, ozoans (Hu, 1986a; Fang et al., 1993; Chen et al., 1994, 1995;

1986a); therefore, it is important to conduct a comprehensive Bian et al., 1996; Chen, 1996). The current study represents

investigation; such detailed palaeontological studies in South a further contribution to the taxonomy of bryozoans from the

Xiazhen Formation of the Zhuzhai section in Yushan County

(Fig. 1). ∗

Corresponding author.

E-mail address: [email protected] (J.Y. Ma).

https://doi.org/10.1016/j.palwor.2018.01.002

344 M. Zhang et al. / Palaeoworld 27 (2018) 343–359

Fig. 1. Map of China showing the South China Block, with enlargement showing the vicinity of Jiangshan, Changshan, and Yushan (JCY area), and the location of

Zhuzhai (adapted from Liang et al., 2016).

2. Stratigraphy 2013), and includes developments of the coral–stromatoporoid

and tetradiid–siliceous sponge patch reef and biostromal units

The northwestward expansion of the Cathaysian Land during (Kwon et al., 2012; Dai et al., 2015; Li et al., 2015; Liang et al.,

the Late Ordovician resulted in the development of the narrow 2016; Lee et al., 2016; Sun et al., 2016; Zhang, 2016). The

shallow-water carbonate Zhe-Gan platform and Zhe-Xi Slope brachiopod communities suggest water depth in the Xiazhen

in the JCY area. Three different depositional settings developed Formation at the Zhuzhai section corresponds to BA2–BA3, and

contemporaneously: low-relief reef of the inner shelf (Xiazhen it was deposited close to the palaeo-shoreline (Zhan et al., 2002).

Formation), carbonate mud mound along the rims of the Recent collection of the index graptolite Anticostia uniformis

shelf (Sanqushan Formation), and ﬁne detrital basinal deposits in the shales suggests the graptolitic biozonations range from

(Changwu Formation) (Zhan and Fu, 1994; Zhang et al., 2007). the Dicellograptus complanatus Biozone to the Diceratograp-

The stratotype section of the Xiazhen Formation is at tus mirus Subzone, indicating a late Katian age for the Xiazhen

Tashan in Yushan County. This unit is also well exposed in Formation here (Chen et al., 2015).

the Zhuzhai section, about 15 km southeast of Yushan County

◦ ◦

(28 34 28.65 N, 118 20 05.45 E) (Fig. 1). The Xiazhen Forma-

3. Material and methods

tion at Zhuzhai, which was ﬁrst described by Chen et al. (1987),

is continuous from northwest to southeast. It has a faulted contact

All bryozoan fossils in this study are collected from beds C9,

with the Jurassic Linshan Group and is overlain by the Lower

C11 in the middle mixed-lithology member and bed C12 in the

Carboniferous outcrops at Zhuzhai Village. Recently, Lee et al.

upper shale member of the ZU1 subsection (Fig. 2). Bryozoans

(2012) published a revised lithostratigraphic work on the three

are relatively abundant in C9 but much less common in C11 and

exposures or sub-sections (ZU1, ZU2, and ZU3) of the Zhuzhai

C12. In total, 215 oriented and unoriented thin sections contain-

section and further subdivided the succession into four litholog-

ing bryozoans were observed using a transmitted light binocular

ical sequences in ascending order: a lower limestone member, a

microscope. Measurements were taken from scaled photographs

lower shale member, a middle mixed-lithology member, and an

of thin sections.

upper shale member, including 20 coral-bearing beds (C0–C19).

Based on published databases of Ordovician bryozoan

The Xiazhen Formation contains abundant brachiopods,

palaeogeography (Tuckey, 1990; Jiménez-Sánchez and Villas,

corals, stromatoporoids, gastropods, cephalopods and trilobites

2010; Jiménez-Sánchez et al., 2015a, 2015b, 2016), two multi-

(Lu et al., 1976; Chen et al., 1987; Zhan and Fu, 1994; Zhan

variate ordination techniques — principal coordinates analysis

and Rong, 1995; Zhan et al., 2002; Zhang et al., 2007; Lee,

(PCO) and detrended correspondence analysis (DCA) — were

M. Zhang et al. / Palaeoworld 27 (2018) 343–359 345

Fig. 2. Lithostratigraphic column and correlation of the Xiazhen Formation in subsections ZU1 at Zhuzhai, South China (adapted from Lee et al., 2012). Specimens

of bryozoans in the present study were collected from intervals C9, C11, C12 (marked by solid circles).

implemented in the program PAST version 2.16 (Hammer et al., 4. Paleogeography of bryozoan fauna

2001) to analyze the palaeobiogeographical relationship of the

bryozoan fauna from the late Katian of the South China Block. Since their ﬁrst appearence in Tremadocian (Xia et al., 2007;

As consistent results were obtained using three different simi- Ma et al., 2015), bryozoans realized its biodiversiﬁcation in Late

larity indices (Dice, Jaccard and Simpson similarity indices) in Ordovician (Taylor and Ernst, 2004; Xia et al., 2010; Ernst,

the PCO analysis, only the plot from the Dice indice is shown in press). During the evolution of Ordovician bryozoans, three

here (Fig. 3). extinction events happened in the early Katian, late Katian, and

346 M. Zhang et al. / Palaeoworld 27 (2018) 343–359

Fig. 3. Principal coordinates analysis (PCO) of the presence/absence generic data matrix, using the Dice similarity coefﬁcient. The percentage of total variation

contained in each coordinate is: axis 1 = 14.21%, axis 2 = 11.35%. The abbreviations and color codes used herein are the same as those in Jiménez-Sánchez and Villas

(2010) to ease comparison. Red: Avalonia; blue: Siberia; dark green: India; green: Laurentia; purple: South China; pink: Mediterranean Area; grey: Altai Sayan;

sky blue: Baltica. Abbreviations used: AI: Anticosti Island; AL: Alabama; AS: Altai Sayan; AV: Avalonia; Bo: Bohemia; CA: Carnic Alps; CK: Central Kentucky;

CM: Central Mongolia; CT: Central Tennessee; EI: Northeast Illinois; Es: Estonia; Ge: Georgia; Go: Gotland; Gr: Greenland; IC: Iberian Chains; Ind: India; Io:

Iowa; Ir: Ireland; Li: Libya; Ma: Manitoba; Mf: Meaford; Mi: Michigan; MN: Montagne Noire; Mo: Morocco; Ms: Missouri; Mt: Manitoulin Island; NK: North

Kentucky; NM: Northwest Mongolia; NZ: Novaya Zemlya; NY: New York; PC: Precordillera Argentina; Sa: Sardinia; SC: South China; SI: South Indiana; SL: Saint

Lawrence River Valley; SM: South Mongolia; SO: South Ohio; Sw: Sweden; Ta: Taimyr; To: Toronto; Tu: Tuva; Vi: Virginia; Wa: Wales; WI: Northwest Illinois;

Wi: Wisconsin; WT: West Texas; Wy: Wyoming. (For interpretation of the references to color in this ﬁgure legend, the reader is referred to the web version of this

article.

Hirnantian, among which the late Katian extinction was most Tashan section (Hu, 1986a) with our new results, there are a

severe (Ernst, in press). total of 18 bryozoan genera in the Yushan area (Homotrypa,

Abundant bryozoans have been documented from Lauren- Dekayia, Batostoma, Heterotrypa, Parvohallopora, Atacto-

tia, Siberia, Baltica, and Mediterranean in the Katian (reviewed porella, Prasopora, Trematopora, Monotrypella, Rhombotrypa,

in Buttler et al., 2013), and their palaeobiogeographical distri- Orbignyella, Constellaria, Stictopora, Trigonodictya, Ptilod-

butions have been discussed (Ross, 1985; Tuckey, 1990; Anstey ictya, Stictoporella, Pseudopachydictya, Nematopora), most of

et al., 2003; Jiménez-Sánchez and Villas, 2010). Three bryozoan which were cosmopolitan during the Ordovician. In the late

provinces — Laurentia–Siberia, Baltica, and Mediterranean — Katian, 12 of these genera (Homotrypa, Dekayia, Batostoma,

have been recognized in the Katian (Tuckey, 1990; Jiménez- Heterotrypa, Parvohallopora, Trematopora, Orbignyella, Con-

Sánchez and Villas, 2010). stellaria, Stictopora, Ptilodictya, Stictoporella, Nematopora)

In this study, ﬁfteen genera of bryozoans are identi- were common elements in the Laurentia–Siberia, Baltica, and

ﬁed from the Zhuzhai section, comprising six genera of Mediterranean provinces; three genera (Atactoporella, Pra-

the Order Trepostomata, six of the Order Cryptostomata, sopora, Monotrypella) occur in the Laurentia–Siberia and

one of the Order Cystoporida, one indeterminate genus of Mediterranean provinces; one genus (Trigonodictya) in the

the Suborder Rhabdomesina and one indeterminate genus of Laurentia–Siberia and Baltica provinces; and two genera (Rhom-

the Order Fenestrata. Four genera (Homotrypa, Prasopora, botrypa, Pseudopachydictya) only in Laurentia. All 18 genera

Constellaria, and Stictopora) have been found previously in Yushan are reported in Laurentia.

in the Tashan section (Hu, 1986a), whereas 11 other gen- The results of our PCO and DCA analyses are mostly

era (Trematopora, Monotrypella, Rhombotrypa, Orbignyella, consistent with previous studies (Jiménez-Sánchez and Villas,

Trigonodictya, Ptilodictya, Stictoporella, Pseudopachydictya, 2010; Jiménez-Sánchez et al.,2016), supporting three bryozoan

Nematopora, Arthrostylidae sp. indet., and Chasmatoporidae provinces (Laurentia–Siberia, Baltica and Mediterranean) in the

sp. indet.) represent ﬁrst discoveries from this area, indicat- late Katian, with the bryozoan fauna from the South China

ing the high diversity of bryozoans in South China Block. Block plotting in the Laurentia–Siberia province convex hull

Combining the bryozoans from the Xiazhen Formation of the (Figs. 3, 4). The bryozoan faunal association of South China

M. Zhang et al. / Palaeoworld 27 (2018) 343–359 347

Fig. 4. Detrended correspondence analysis (DCA) of the presence/absence generic data matrix. The abbreviations and color codes are the same as those used in

Fig. 3.

Block is similar to the age-equivalent Laurentia–Siberia units, 0.09–0.25 mm wide, bending gently in exozone, intersecting

◦

possibly due to their similar environmental parameters and low colony surface at an angle of 55–65 or sometimes nearly

palaeolatitudes. perpendicular to the colony surface. Autozooidal walls thin

and undulating in endozone, thickened and with dark narrow

5. Systematic palaeontology serrated medial line and a few mural spines in exozone. Auto-

zooidal diaphragms numerous, thin, planar sometimes inclined,

The material is housed at Nanjing Institute of Geology and closely spaced, 0.09–0.24 mm apart in the endozone, slightly

Palaeontology, Chinese Academy of Sciences, under numbers more concentrated in the exozone, spaced 0.06–0.20 mm apart,

NIGP166955–166976. often absent in outermost exozone. Cystiphragms only in

exozone, two types well developed: type I, densely overlap-

Phylum Bryozoa Ehrenberg, 1831 ping, spaced 0.02–0.09 mm apart; type II, vesicular, slightly

overlapping or isolated on one or two sides of the wall, widely

Class Stenolaemata Borg, 1926

spaced, 0.09–0.20 mm apart. Mesozooids rare, developed from

Superoder Palaeostomata Ma et al., 2014 the middle part of exozone, containing planar or sometimes

concave diaphragms. Acanthostyles restricted to exozone,

Order Trepostomida Ulrich, 1882

mostly along the wall.

Suborder Halloporina Astrova, 1965

Remarks. Homotrypa yushanensis Hu, 1986a is similar to

Family Monticuliporidae Nicholson, 1881

Homotrypa pulchra Bassler, 1903 from the Upper Ordovician

Genus Homotrypa Ulrich, 1882 of North America, but the former has more acanthostyles and

mesozooids, whereas these are rare or absent in the latter.

Homotrypa yushanensis Hu, 1986a

Homotrypa yushanensis differs from Homotrypa ramulosa

(Fig. 5A–C; Appendix A Table A1) Bassler, 1903 in having more well-developed cystiphragms,

diaphragms and mesozooids.

1986a Homotrypa yushanensis – Hu, p. 168, pl. I, ﬁgs. 1–5.

Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

Description. Branched colonies, branch diameter

Bed C9, Zhuzhai section, Yushan County, Jiangxi Province,

2.00–2.14 mm. Endozone 0.96–1.28 mm wide, exozone

East China.

0.24–0.55 mm wide. Autozooids long, polygonal in endozone,

348 M. Zhang et al. / Palaeoworld 27 (2018) 343–359

Fig. 5. (A–C) Homotrypa yushanensis Hu, 1986a; (A) longitudinal section, scale bar = 0.5 mm; (B) longitudinal section, scale bar = 0.2 mm; (C) transverse section,

scale bar = 0.2 mm. (D–F) Homotrypa sp.; (D) longitudinal section, scale bar = 0.5 mm; (E) longitudinal section, scale bar = 0.1 mm; (F) transverse section, scale

bar = 0.1 mm. (G–H) Prasopora yushanensis Hu, 1986a; (G) longitudinal section, scale bar = 0.2 mm; (H) longitudinal section, scale bar = 0.2 mm. (I–K) Trematopora

sp.; (I) longitudinal section, scale bar = 0.2 mm; (J) tangential section, scale bar = 0.1 mm; (K) transverse section, scale bar = 0.1 mm.

M. Zhang et al. / Palaeoworld 27 (2018) 343–359 349

Material. NIGP166955. Prasopora falesi (James, 1884) from the Upper Ordovician

of North America in having fewer mesozooids, but more and

Homotrypa sp.

closely spaced cystiphragms in the autozooids.

(Fig. 5D–F; Appendix A Table A2)

Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

Description. Branched colonies, branch diameter about Bed C9, Zhuzhai section, Yushan County, Jiangxi Province,

1.47 mm. Endozone 0.56–0.70 mm and exozone 0.30–0.37 mm East China.

wide. Autozooids parallel to branch axis for a long distance,

Material. NIGP166957.

then inclined gently in the endozone, and later bending sharply

in transitional region between endozone and exozone, inter- Family Trematoporidae Miller, 1889

secting branch surface at right angles. Autozooids polygonal

Genus Trematopora Hall, 1852

in endozone, 0.12–0.19 mm wide. Autozooidal walls thin

and undulating in inner endozone, distinctly thickened in Trematopora sp.

outer endozone to exozone, with dark narrow serrated medial

(Fig. 5I–K; Appendix A Table A4)

line and well-deﬁned boundary. Autozooidal diaphragms

Description. Colony branched, branches 1.48–1.56 mm wide.

well developed, thin, straight or inclined, closely spaced,

Endozone 0.67–0.92 mm wide; exozone 0.16–0.33 mm wide.

0.05–0.15 mm apart in endozone; much more densely spaced,

Autozooidal apertures rounded to oval, 0.11–0.18 mm by

0.03–0.09 mm apart in exozone, often absent in outermost

0.09–0.13 mm in diameter; evenly distributed, separated

exozone. Cystiphragms occurring in exozone, usually restricted

from each other, spaced 0.20–0.28 mm apart, with distinct

to one side of the zooids, large, vesicular, slightly overlapping

peristomes, 0.02–0.04 mm thick. Autozooidal diaphragms

or just contiguous, joining diaphragms on the other side of

rare and widely spaced, planar. Autozooids bend abruptly

wall, spaced 0.08–0.15 mm apart, not densely overlapping,

in exozone, intersecting the colony surface nearly at right

3–5 in each zooid. Mesozooids rare, present locally, small.

angles. Endozone recrystallized and indistinct. Autozooidal

Acanthostyles rare, small, occurring at autozooidal corners.

walls thickened, with reverse V-shaped lamination in exozone.

Remarks. Homotrypa sp. differs from Homotrypa yushanensis

Mesozooids rounded, 0.09–0.10 mm wide, commonly 1–2,

Hu, 1986a in its narrower branches and endozone, more

locally 3–4 surrounding each autozooid. Acanthostyles small,

closed spaced diaphragms, rare and indistinct mesozooids and

0.02–0.03 mm in diameter, locally 2–4 per autozooid, some

acanthostyles and differs from Homotrypa pulchra Bassler,

slightly inﬂecting the autozooidal apertures.

1903 in narrower branches, fewer cystiphragms.

Remarks. This specimen is similar to the Trematopora sp. 1 of

Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

Ernst and Key (2007) from the Upper Ordovician of France

Bed C9, Zhuzhai section, Yushan County, Jiangxi Province,

but has fewer autozooidal diaphragms and acanthostyles, and

East China.

mesozooids are lacking from parts of the longitudinal section.

Material. NIGP166956.

Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

Genus Prasopora Nicholson and Etheridge, 1877 Bed C9, Zhuzhai section, Yushan County, Jiangxi Province,

East China.

Prasopora yushanensis Hu, 1986a

Material. NIGP166958.

(Fig. 5G–H; Appendix A Table A3)

Suborder Amplexoporina Astrova, 1965

1986a Prasopora yushanensis – Hu, p. 172, pl. II, ﬁgs. 7–9; pl. III, ﬁg. 1.

2007 Prasopora yushanensis Hu – Suttner and Ernst, p. 1491, pl. 3, ﬁgs. Family Amplexoporidae Miller, 1889

1–3.

Genus Monotrypella Ulrich, 1882

Description. Colony encrusting. Autozooids bud from basal

Monotrypella sp.

wall, are recumbent near the base for a short distance before

bending abruptly to become upright, intersecting the colony sur- (Fig. 6A–C; Appendix A Table A5)

face nearly at right angles in longitudinal section. Cystiphragms

Description. Colonies branched, branches 1.45–1.51 mm

abundant, closely overlapping on one or two sides of wall,

in diameter. Endozone 1.94–2.07 mm wide; exozone

spaced 0.03–0.18 mm apart, joining to planar diaphragms on

0.62–0.83 mm wide. Autozooidal apertures subrounded to

the other side or in the middle of zooecia. Diaphragms straight

polygonal, 0.28–0.34 mm long, 0.20–0.33 mm wide, spaced

or inclined, closely spaced, 0.03–0.13 mm apart. Mesozooids

0.26–0.46 mm apart, possessing thin lamellar peristomes.

few in number, originating from exozone, with dense straight

Autozooids polygonal in endozone. Diaphragms straight, rarely

or slightly curved diaphragms. Acanthostyles abundant, well

inclined, concentrated mostly in transitional region between

developed along the wall.

endozone and exozone, absent in outer exozone, 2–3 in each

Remarks. Prasopora yushanensis differs from Prasopora autozooid. Wall thin in endozone, thickened with dark narrow

grayae Nicholson and Etheridge, 1877 from the Middle–Upper serrated medial line in exozone, containing discontinuous

Ordovician of Europe in having fewer mesozooids, smaller and granular material between contiguous autozooids. Mesozooids

closely spaced cystiphragms in the autozooids and differs from rare and small, locally present among autozooids, subrounded,

350 M. Zhang et al. / Palaeoworld 27 (2018) 343–359

Fig. 6. (A–C) Monotrypella sp.; (A) tangential section, scale bar = 0.2 mm; (B) tangential section, scale bar = 0.1 mm; (C) transverse section, scale bar = 0.5 mm.

(D–E) Rhombotrypa sp.; (D) transverse section, scale bar = 0.2 mm; (E) transverse section, scale bar = 0.1 mm. (F–H) Orbignyella sp.; (F) longitudinal section,

scale bar = 0.5 mm; (G) transverse section, scale bar = 0.1 mm; (H) tangential section, scale bar = 0.1 mm. (I–J) Constellaria jiangxiensis Hu, 1986a; (I) longitudinal

section, scale bar = 0.5 mm; (J) tangential section, scale bar = 0.2 mm. (K–M) Constellaria sp.; (K) longitudinal section, scale bar = 0.5 mm; (L) longitudinal section,

scale bar = 0.2 mm; (M) longitudinal section, scale bar = 0.2 mm. (N–P) Stictopora nicholsoni (Ulrich, 1882); (N) transverse section, scale bar = 0.1 mm; (O) oblique

tangential section, scale bar = 0.5 mm; (P) oblique tangential section, scale bar = 0.1 mm.

M. Zhang et al. / Palaeoworld 27 (2018) 343–359 351

0.10–0.21 mm wide. Acanthostyles absent. Suborder Fistuliporina Astrova, 1964

Remarks. This specimen is similar to Monotrypella boonvil- Family Constellariidae Ulrich, 1896

lensis Ross, 1970 from the Upper Ordovician of USA, but

Genus Constellaria Dana, 1846

has a wider exozone, no incomplete diaphragms and fewer

mesozooids. Constellaria jiangxiensis Hu, 1986a

Occurrence. Upper Ordovician, Katian, Xiazhen Formation, (Fig. 6I–J; Appendix A Table A8)

Bed C9, Zhuzhai section, Yushan County, Jiangxi Province,

1986a Constellaria jiangxiensis – Hu, p. 179, pl. V, ﬁgs. 1–6.

East China.

Description. Colony encrusting. Autozooids inclined or upright

Material. NIGP166959.

from basal wall above substrate, intersecting the colony sur-

Genus Rhombotrypa Ulrich and Bassler, 1904 face at right angles. Autozooidal walls thin, undulating, obscure.

Autozooids contiguous, sometimes separated by mesozooids.

Rhombotrypa sp.

Diaphragms straight, rarely curved, numerous and densely

(Fig. 6D–E; Appendix A Table A6) spaced, 0.03–0.12 mm apart. Mesozooids few in number,

often concentrated in clusters, diaphragms densely spaced,

Description. Colonies branched, branches 2.77–3.00 mm

0.02–0.08 mm apart. Autozooidal apertures rounded or ellipti-

in diameter. Endozone 1.46–1.60 mm wide; exozone

cal, large, 0.12–0.23 mm by 0.10–0.18 mm in diameter, spaced

0.70–0.90 mm wide. Autozooids regularly quadrate or

0.15–0.32 mm apart. Mesozooidal apertures elliptical, small,

rhombic in axial region of inner endozone, 0.18–0.28 mm

0.04–0.06 mm wide. Acanthostyles small and distinct. Stellate

in diameter. Autozooidal wall thin in endozone, distinctly

monticules composed of autozooids and mesozooids, with thick-

thickened in exozone, displaying narrow dark serrated medial

ened wall, surrounded by concentric lamellar layers.

line. Some autozooids irregularly polygonal, 0.10–0.13 mm in

diameter, interpreted as either young autozooids squeezed and Remarks. Constellaria jiangxiensis is similar to Constellaria

deformed or small rhombic mesozooids. islensis Ross, 1963 and Constellaria antheloidea (Hall, 1847)

from the Upper Ordovician of the USA (Ross, 1963), but Con-

Remarks. This specimen differs from Rhombotrypa quadratus

stellaria jiangxiensis has more densely spaced diaphragms.

(Rominger, 1866) in having irregular autozooids in the outer

endozone and thinner walls in the endozone. Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

Bed C12, Zhuzhai section, Yushan County, Jiangxi Province,

Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

East China.

Bed C12, Zhuzhai section, Yushan County, Jiangxi Province,

East China. Material. NIGP166963.

Material. NIGP166960. Constellaria sp.

Family Atactotoechidae Duncan, 1939 (Fig. 6K–M; Appendix A Table A9)

Genus Orbignyella Ulrich and Bassler, 1904 Description. Colony encrusting. Autozooids initially inclined

and later subperpendicular to the substrate. Stellate monticules

Orbignyella sp.

consisting of clusters of abundant mesozooids, low or raised.

(Fig. 6F–H; Appendix A Table A7)

Mesozooidal walls thin, mostly obscure or indistinct because of

Description. Colony lamellate. Autozooids regularly angular, recrystallization. In a cluster of mesozooids, diaphragms straight

most hexagonal or pentagonal, contiguous, 0.18–0.25 mm in and densely spaced, spaced 0.02–0.10 mm (mean 0.05 mm)

diameter. Acanthostyles well developed, moderately large, apart, sometimes forming thickened transverse lamellae, inter-

irregularly triangular, granular, 0.03–0.04 mm in diameter, preted as possible growth rhythm layers; inclined or vesicular,

located at autozooidal corners. Diaphragms straight or inclined, overlapping cystiphragms are locally abundant. Rays con-

sometimes curved, spaced 0.16–0.26 mm apart. Autozooidal sisting of several rows of autozooids, with diaphragms less

wall thin with obscure boundary in endozone, thickened with closely spaced than in the mesozooids, 0.04–0.18 mm (mean

wide serrated medial line in exozone. Mesozooids rare, narrow, 0.10 mm) apart, straight or rarely inclined. Acanthostyles dis-

with straight diaphragms, spaced 0.09–0.14 mm apart. tinct, thickening the autozooidal wall, up to 0.05–0.08 mm thick.

Autozooids contiguous, sometimes separated by mesozooids.

Remarks. This specimen is similar to Orbignyella sublamellosa

In tangential section, autozooidal apertures rounded or ellipti-

Ulrich and Bassler, 1904, as redescribed by Astrova (1978), but

cal, 0.13–0.18 mm in diameter; mesozooidal apertures elliptical,

has rare mesozooids and fewer diaphragms.

small; acanthostyles indistinct; walls thick, zooecia surrounded

Occurrence. Upper Ordovician, Katian, Xiazhen Formation, by concentric lamellar layers in stellate monticules.

Bed C9, C12, Zhuzhai section, Yushan County, Jiangxi

Remarks. Constellaria sp. differs from Constellaria jiangxien-

Province, East China.

sis Hu, 1986a in having less closely-spaced diaphragms in the

Material. NIGP166961, NIGP166962. autozooids and mesozooids, though more closely-spaced than

in other species of the genus Constellaria, fewer autozooids,

Order Cystoporata Astrova, 1964

352 M. Zhang et al. / Palaeoworld 27 (2018) 343–359

and locally-inclined diaphragms or overlapping vesicular cys- Mesotheca straight, about 0.01 mm thick, but with indistinct

tiphragms. structure possibly because of poor preservation. Autozooids

semicircular to irregularly quadrangular in endozone, regularly

Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

arranged. Walls thin and distinct in endozone. Extrazooidal

Bed C12, Zhuzhai section, Yushan County, Jiangxi Province,

skeletal deposits well developed. Laminar stereom containing

East China.

abundant mural styles in exozone.

Material. NIGP166964, NIGP166965.

Remarks. Trigonodictya parvula Ernst and Carrera, 2012 differs

Order Cryptostomida Vine, 1884 from the other Trigonodictya species in its smaller dimensions

and the absence of vesicular skeleton (Ernst and Carrera, 2012).

Suborder Ptilodictyina Astrova and Morozova, 1956

The Xiazhen Formation specimen is similar to T. parvula from

Family Rhinidictyidae Ulrich, 1893

the Upper Ordovician of Argentina in autozooidal shape in trans-

Genus Stictopora Hall, 1847 verse section and the presence of mural styles in the exozone, but

differs in the smaller size of the autozooids in transverse section.

Stictopora nicholsoni (Ulrich, 1882)

Median rods and the three-layered structure of the mesotheca

(Figs. 6N–P, 7A–B; Appendix A Table A10) have not been observed in the Chinese material, possibly because

of poor preservation.

1882 Rhinidictya nicholsoni – Ulrich, p. 152.

1953 Rhinidictya nicholsoni Ulrich – Bassler, p. G140, ﬁg. 100.1a–d.

Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

1983 Stictopora nicholsoni (Ulrich) – Karklins, p. 507, ﬁg. 251.1a–f.

Bed C9, C12, Zhuzhai section, Yushan County, Jiangxi Province,

1993 Rhinidictya nicholsoni Ulrich – Gorjunova and Lavrentjeva, p. 42,

East

pl. II, ﬁgs. 4, 5. China.

2011b Rhinidictya nicholsoni Ulrich – Chang et al., p. 414, pl. III, ﬁgs.

Material. NIGP166968, NIGP166969.

5–8.

Family Ptilodictyidae Zittel, 1880

Description. Colony bifoliate, branches 1.36 mm wide by

0.62 mm deep. Endozone 0.10–0.14 mm thick, exozone Genus Ptilodictya Lonsdale, 1839

0.19–0.20 mm thick. Mesotheca straight, 0.02–0.04 mm thick

Ptilodictya ensiformis (Hall, 1852)

through most of the colony, obscure at the outer ends, contain-

ing a few subelliptical median rods, about 0.01 mm in diameter. (Fig. 7D–E; Appendix A Table A12)

Autozooids alternately arranged on two sides of mesotheca.

1852 Phaenopora ensiformis – Hall, p. 48, pl. 16, ﬁg. 8a–c.

Autozooids rectangular, the thin transverse walls nearly per- 1960 Ptilodictya ensiformis (Hall) – Ross, p. 1067, pl. 126, ﬁgs. 4–6.

pendicular to the longitudinal walls, which are 0.02–0.04 mm

Description. Colony very slender, 1.26 mm wide and 0.30 mm

thick in endozone, expanding to 0.08–0.13 mm thick, with a

deep. Endozone 0.09–0.12 mm thick, exozone 0.04–0.05 mm

well-deﬁned boundary in the exozone. Autozooidal apertures

thick. Mesotheca narrow and straight, about 0.02 mm wide,

elliptical, 0.15–0.19 mm by 0.07–0.10 mm, arranged in alter-

medium granular layer discontinuous or beaded without median

nating rows, spaced 0.31–0.33 mm apart longitudinally and

rods. Autozooids rectangular in the endozone, regularly aligned

0.21–0.26 mm diagonally. One serie of acanthostyles occurring

on each side of the mesotheca. Autozooidal longitudinal wall

in the autozooidal walls between adjacent autozooids.

slender, containing a few mural styles in exozone. Autozooidal

Remarks. Except the poor preservation of the median rods, this apertures oval, 0.12–0.25 mm by 0.06–0.07 mm, arranged

specimen is similar to Stictopora nicholsoni (Ulrich, 1882). It in regular longitudinal rows, spaced apart 0.25–0.32 mm

is also similar to Stictopora blackensis Ross, 1964 in the longi- longitudinally and 0.17–0.21 mm diagonally. Mesozooids and

tudinal aligned acanthostyles, but differs from the latter in the acanthostyles not observed.

wider colonies and more elongated apertures.

Remarks. Ptilodictya ensiformis (Hall, 1852) differs from

Occurrence. Upper Ordovician, Katian, Xiazhen Formation, Ptilodictya sulcata Billings, 1866 in its slender colony, smaller

Bed C9, Zhuzhai section, Yushan County, Jiangxi Province, East autozooids, and smaller spacing longitudinally and laterally

China. between autozooidal apertures.

Material. NIGP166966, NIGP166967. Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

Bed C9, C11, Zhuzhai section, Yushan County, Jiangxi

Genus Trigonodictya Ulrich, 1893

Province, East China.

Trigonodictya parvula Ernst and Carrera, 2012

Material. NIGP166970, NIGP166971.

(Fig. 7C; Appendix A Table A11)

Family Stictoporellidae Nickles and Bassler, 1900

2012 Trigonodictya parvula – Ernst and Carrera, p. 739, ﬁgs.

Stictoporella

12.8–12.10, 13.1–13.3. Genus Ulrich, 1882

Description. Colony branches elliptical with blunt rounded Stictoporella sp.

ends in transverse section, 0.36 mm wide and 0.29 mm deep.

(Fig. 7F–G; Appendix A Table A13)

Endozone 0.06–0.09 mm thick, exozone 0.05–0.06 mm thick.

Description. Colony bifoliate, 3.61 mm wide and 0.60 mm

M. Zhang et al. / Palaeoworld 27 (2018) 343–359 353

Fig. 7. (A–B) Stictopora nicholsoni (Ulrich, 1882), transverse sections, scale bar = 0.2 mm. (C) Trigonodictya parvula Ernst and Carrera, 2012, transverse section, scale

bar = 0.1 mm. (D–E) Ptilodictya ensiformis (Hall, 1852); (D) transverse section, scale bar = 0.2 mm; (E) tangential section, scale bar = 0.1 mm. (F–G) Stictoporella sp.;

(F) oblique longitudinal section, scale bar = 0.2 mm; (G) oblique longitudinal section, scale bar = 0.1 mm. (H–I) Pseudopachydictya sp.; (H) tangential section, scale

bar = 0.2 mm; (I) tangential section, scale bar = 0.1 mm. (J) Nematopora sp., transverse section, scale bar = 0.1 mm. (K) Arthrostylidae sp. indet., oblique transverse

section, scale bar = 0.1 mm. (L) Chasmatoporidae sp. indet., oblique longitudinal section, scale bar = 0.1 mm.

354 M. Zhang et al. / Palaeoworld 27 (2018) 343–359

thick. Endozone 0.09–0.12 mm thick, exozone 0.14–0.18 mm or triangular in transverse section in endozone, budding from

thick. Mesotheca straight, locally zigzag, about 0.02 mm median axis. Longitudinal wall continuous, extending from

wide, medium granular layer without median rods throughout axial region to colony surface and zooidal boundaries well

mesotheca. Autozooids alternately arranged on two sides deﬁned. Extrazooidal skeleton well developed, with common

of mesotheca. Inferior hemisepta curve proximally from styles on ridges. Heterozooids absent.

mesotheca, variable in shape, comprising two types, long thin

Remarks. This specimen is similar to Nematopora hispida

and short blunt hemispeta. Extrazooidal stereom laminar, thick,

Conti, 1990, as described from the Upper Ordovician of France

poorly preserved. Mesozooids not observed.

by Ernst and Key (2007), but differs in having a median wall

Remarks. The specimen is similar to the cryptostome ﬁgured without observable median rods possibly due to the poor

by Ross and Ross (2007) and to the Stictoporella sp. of Chang preservation.

et al. (2011b).

Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

Occurrence. Upper Ordovician, Katian, Xiazhen Formation, Bed C9, Zhuzhai section, Yushan County, Jiangxi Province,

Bed C9, Zhuzhai section, Yushan County, Jiangxi Province, East China.

East China.

Material. NIGP166974.

Material. NIGP166972.

Arthrostylidae sp. indet.

Family Virgatellidae Astrova, 1965

(Fig. 7K; Appendix A Table A16)

Genus Pseudopachydictya Astrova, 1965

Description. Colony with branches of elliptical trans-

Pseudopachydictya sp. verse section, 0.64 mm by 0.33 mm in diameter. Endozone

0.07–0.13 mm wide, exozone 0.08–0.14 mm wide. Axial region

(Fig. 7H–I; Appendix A Table A14)

with a well-deﬁned median axis. Autozooids in transverse

Description. Colony with long branches, branches section subtriangular or rounded, radially arranged, centered on

0.74–0.79 mm wide. Autozooidal apertures oval, 0.13–0.16 mm axis in endozone. Extrazooidal skeleton well developed with

by 0.05–0.07 mm, widely spaced, 0.35–0.41 mm apart lon- abundant styles, perpendicular to colony surface. Autozooidal

gitudinally and 0.24–0.32 mm diagonally, most arranged wall microstructure obscure, locally distinct.

diagonally, locally in straight ranges, oblique to midregion of

Remarks. This specimen is similar to Arthroclema Billings,

branch in tangential section. Autozooidal apertures containing

1865 in zooidal shape and arrangement, and in the pres-

peristomes, 0.03–0.04 mm thick. Mesozooids not observed.

ence of the styles in the exozone. The genus Arthroclema

Acanthostyles common, densely packed around apertures or

is characterised by a well-deﬁned linear axis; zooids are

located in the extrazooidal skeleton, rounded, moderately large,

subtriangular, rounded in transverse section in the endozone;

0.01–0.02 mm in diameter, with hyaline cores and dark thin

the extrazooidal skeleton is well developed with scattered to

sheaths.

common paurostyles usually developed on ridges (following

Remarks. This specimen is similar to Pseudopachydictya Blake, 1983). However, some characters of the specimen, such

multicapillaris (Astrova, 1955) in tangential section but differs as growth habit and articulation joints, are unknown because

in its narrower branches. Because of the lack of other characters, of few sections available and poor preservation for a deﬁnite

such as diaphragms, the limited available material does not assignment.

allow detailed description.

Occurrence. Upper Ordovician, Katian, Xiazhen Formation,

Occurrence. Upper Ordovician, Katian, Xiazhen Formation, Bed C12, Zhuzhai section, Yushan County, Jiangxi Province,

Bed C11, Zhuzhai section, Yushan County, Jiangxi Province, East China.

East China.

Material. NIGP166975.

Material. NIGP166973.

Order Fenestrata Astrova and Morozova, 1956

Suborder Rhabdomesina Astrova and Morozova, 1956

Suborder Phylloporinina Lavrentjeva, 1979

Family Arthrostylidae Ulrich, 1882

Family Chasmatoporidae Schulga-Nesterenko, 1955

Genus Nematopora Ulrich, 1888

Chasmatoporidae sp. indet.

Nematopora sp.

(Fig. 7L; Appendix A Table 17)

(Fig. 7J; Appendix A Table A15)

Description. Colony fenestrate, branches 0.43–0.44 mm

Description. Colony with branches nearly circular in trans- in diameter. Endozone 0.25–0.26 mm wide, exozone

verse section, 0.37 mm by 0.35 mm in diameter. Endozone 0.09–0.11 mm wide. Fenestrules short, in 2–4 rows, stri-

0.07–0.12 mm thick, exozone 0.05–0.08 mm thick. Axial region ated on reverse side of branches, 0.07–0.10 mm wide each

with a well deﬁned median axis. Planar median wall about row in longitudinal section. Diaphragms and hemisepta not

0.01 mm thick, median rods not observed. Autozooids rounded observed. Fenestrules oval, 0.04–0.05 mm wide. Extrazooidal

M. Zhang et al. / Palaeoworld 27 (2018) 343–359 355

skeleton thick, nodes not seen. Table A3

Descriptive statistics of Prasopora yushanensis Hu, 1986a. Abbreviations as in

Remarks. This specimen resembles Chasmatopora Eichwald, Appendix A Table A1. All measurements in mm.

1855 (see detailed description in Ernst and Key, 2007).

N X SD CV MIN MAX

However, only the reverse surface of the specimen is available,

Diaphragm spacing 66 0.07 0.025 0.04 0.03 0.13

which precludes certain generic assignment of this bryozoan.

Cystiphragm spacing 85 0.08 0.03 0.04 0.03 0.18

Occurrence. Upper Ordovician, Katian, Xiazhen Formation, Acanthostyle diameter 9 0.03 0.005 0.02 0.02 0.04

Bed C9, Zhuzhai section, Yushan County, Jiangxi Province,

East China.

Table A4

Material. NIGP166976.

Descriptive statistics of Trematopora sp. Abbreviations as in Appendix A

Table A1. All measurements in mm.

Acknowledgements

N X SD CV MIN MAX

Branch width 5 1.51 0.041 0 1.48 1.56

This paper was supported by the National Natural Sci-

Endozone width 5 0.81 0.091 0.01 0.67 0.92

ence Foundation of China (NSFC, 41472008, 41521061 and

Exozone width 5 0.25 0.066 0.03 0.16 0.33

41290260) and SKLPS, and is a contribution to the IGCP Project

Aperture length 20 0.14 0.015 0.01 0.11 0.18

653: the Onset of the Great Ordovician Biodiversiﬁcation Event

Aperture width 15 0.11 0.011 0.01 0.09 0.13

(GOBE). We are grateful to Mark A. Wilson and Caroline J. Peristome width 13 0.03 0.005 0.02 0.02 0.04

Aperture spacing 18 0.24 0.026 0.01 0.20 0.28

Buttler for their helpful comments to this manuscript.

Mesozooecia width 3 0.09 0.001 0 0.09 0.10

Acanthostyle diameter 6 0.02 0.005 0.02 0.02 0.03

Appendix A.

Table A5

Table A1

Descriptive statistics of Monotrypella sp. Abbreviations as in Appendix A

Descriptive statistics of Homotrypa yushanensis Hu, 1986a. Abbreviations: N –

Table A1. All measurements in mm.

number of measurements; X – mean; SD – standard deviation; CV – coefﬁcient

of variation; MIN – minimal value; MAX – maximal value. All measurements

N X SD CV MIN MAX

in mm.

Branch width 5 1.46 0.039 0 1.45 1.51

N X SD CV MIN MAX

Endozone width 5 1.99 0.052 0 1.94 2.07

Exozone width 5 0.72 0.098 0.01 0.62 0.83

Branch width 5 2.05 0.054 2.61 2.00 2.14

Aperture length 22 0.31 0.021 0.01 0.28 0.34

Endozone width 5 1.09 0.141 12.99 0.96 1.28

Aperture width 23 0.25 0.033 0.01 0.20 0.33

Exozone width 8 0.36 0.11 30.21 0.24 0.55

Aperture spacing 33 0.34 0.05 0.02 0.26 0.46

Autozooecial width 27 0.15 0.036 23.20 0.09 0.25

Mesozooecia width 3 0.17 0.059 0.04 0.10 0.21

Mesozooecial width in transverse 8 0.07 0.013 18.89 0.06 0.09

section

Diaphragms spacing in endozone 28 0.16 0.042 25.54 0.09 0.24

Diaphragms spacing in exozone 27 0.12 0.036 29.78 0.06 0.20 Table A6

Cystiphragm spacing – type I 21 0.14 0.031 23.05 0.09 0.20 Descriptive statistics of Rhombotrypa sp. Abbreviations as in Appendix A

Cystiphragm spacing – type II 40 0.05 0.014 32.03 0.02 0.09 Table A1. All measurements in mm.

N X SD CV MIN MAX

Branch width 4 2.86 0.102 3.57 2.77 3.00

Table A2

Endozone width 5 1.54 0.052 3.37 1.46 1.60

Descriptive statistics of Homotrypa sp. Abbreviations as in Appendix A

Exozone width 5 0.79 0.087 11.02 0.70 0.90

Table A1. All measurements in mm.

Autozooecia width 23 0.23 0.032 14.05 0.18 0.28

N X SD CV MIN MAX Mesozooecia width 3 0.11 0.018 15.83 0.10 0.13

Endozone width 5 0.63 0.054 8.56 0.56 0.70

Exozone width 5 0.34 0.024 6.97 0.30 0.37

Table A7

Autozooecia width in transverse 14 0.15 0.027 18.16 0.12 0.19

section Descriptive statistics of Orbignyella sp. Abbreviations as in Appendix A

Table A1. All measurements in mm.

Diaphragm spacing in endozone 39 0.09 0.026 29.15 0.05 0.15

Diaphragm spacing in exozone 30 0.05 0.015 31.04 0.03 0.09

N X SD CV MIN MAX

Cystiphragm spacing in exozone 27 0.11 0.02 18.71 0.08 0.15

Autozooecia width in transverse 9 0.21 0.022 10.85 0.18 0.25

section

Autozooecia spacing 18 0.23 0.016 7.13 0.20 0.26

Acanthostyle diameter in transverse 5 0.03 0.004 11.50 0.03 0.04

section

Diaphragm spacing in autozooecia 9 0.20 0.032 16.16 0.16 0.26

Diaphragm spacing in mesozooecia 4 0.11 0.024 21.75 0.09 0.14

356 M. Zhang et al. / Palaeoworld 27 (2018) 343–359

Table A8 Table A13

Descriptive statistics of Constellaria jiangxiensis Hu, 1986a. Abbreviations as Descriptive statistics of Stictoporella sp. Abbreviations as in Appendix A

in Appendix A Table A1. All measurements in mm. Table A1. All measurements in mm.

N X SD CV MIN MAX N X SD CV MIN MAX

Diaphragm spacing in 54 0.07 0.022 31.80 0.03 0.12 Endozone width 9 0.11 0.008 7.79 0.09 0.12

autozooecia Exozone width 5 0.16 0.017 10.55 0.14 0.18

Diaphragm spacing in 43 0.05 0.013 28.92 0.02 0.08 Mesotheca width 5 0.02 0 0 0.02 0.02

mesozooecia

Aperture length 22 0.19 0.022 11.48 0.12 0.23

Aperture width 24 0.14 0.022 15.18 0.10 0.18 Table A14

Aperture spacing 35 0.22 0.041 18.88 0.15 0.32 Descriptive statistics of Pseudopachydictya sp. Abbreviations as in Appendix A

Mesozooecia aperture width 9 0.05 0.006 13.81 0.04 0.06 Table A1. All measurements in mm.

N X SD CV MIN MAX

Table A9

Descriptive statistics of Constellaria sp. Abbreviations as in Appendix A Branch width 5 0.76 0.027 3.49 0.74 0.79

Table A1. All measurements in mm. Aperture length 7 0.15 0.013 9.21 0.13 0.16

Aperture width 7 0.06 0.005 9.01 0.05 0.07

N X SD CV MIN MAX

Peristome thickness 4 0.03 0.002 7.40 0.03 0.04

Aperture spacing diagonally 8 0.26 0.027 10.17 0.24 0.32

Diaphragm spacing in 56 0.10 0.031 31.71 0.04 0.18

autozooecia Aperture spacing along branch 7 0.37 0.026 7.06 0.35 0.41

Acanthostyle diameter 41 0.01 0.003 24.75 0.01 0.02

Diaphragm spacing in 96 0.05 0.016 31.53 0.02 0.10

mesozooecia

Aperture width 11 0.16 0.015 9.73 0.13 0.18

Table A15

Descriptive statistics of Nematopora sp. Abbreviations as in Appendix A

Table A10

Table A1. All measurements in mm.

Descriptive statistics of Stictopora nicholsoni (Ulrich, 1882). Abbreviations as

in Appendix A Table A1. All measurements in mm. N X SD CV MIN MAX

N X SD CV MIN MAX Endozone width 4 0.10 0.021 21.84 0.07 0.12

Exozone width 5 0.06 0.012 18.90 0.05 0.08

Endozone width 4 0.12 0.018 15.08 0.10 0.14

Mesotheca width 5 0.01 0 0 0.01 0.01

Exozone width 3 0.19 0.008 4.23 0.19 0.20

Longitudinal wall width in 9 0.03 0.006 19.07 0.02 0.04 endozone

Table A16

Longitudinal wall width in 7 0.10 0.015 15.40 0.08 0.13

Descriptive statistics of Arthrostylidae sp. indet. Abbreviations as in Appendix

exozone

A Table A1. All measurements in mm.

Mesotheca width 5 0.03 0.005 17.75 0.02 0.04

Median rod diameter 3 0.01 0 0 0.01 0.01 N X SD CV MIN MAX

Aperture length 13 0.17 0.012 7.22 0.15 0.19

Endozone width 4 0.10 0.026 26.59 0.07 0.13

Aperture width 11 0.08 0.014 17.32 0.07 0.10

Exozone width 5 0.11 0.024 22.12 0.08 0.14

Aperture spacing across branch 11 0.23 0.017 7.53 0.21 0.26

Aperture spacing along branch 5 0.32 0.009 2.85 0.31 0.33

Acanthostyle diameter 18 0.02 0.005 26.98 0.01 0.03

Table A17

Descriptive statistics of Chasmatoporidae sp. indet. Abbreviations as in

Table A11

Appendix A Table A1. All measurements in mm.

Descriptive statistics of Trigonodictya parvula Ernst and Carrera, 2012. Abbre-

viations as in Appendix A Table A1. All measurements in mm. N X SD CV MIN MAX

N X SD CV MIN MAX Branch width 5 0.43 0.007 1.58 0.43 0.44

Endozone width 3 0.26 0.007 2.91 0.25 0.26

Endozone width 5 0.07 0.009 12.91 0.06 0.09

Exozone width 5 0.10 0.008 8.06 0.09 0.11

Exozone width 5 0.06 0.004 6.60 0.05 0.06

Row width 5 0.09 0.009 10.45 0.07 0.10

Mesotheca width 5 0.01 0 0 0.01 0.01

Fenestrule width 5 0.05 0.003 5.58 0.04 0.05

Table A12

Descriptive statistics of Ptilodictya ensiformis (Hall, 1852). Abbreviations as in

Appendix A Table A1. All measurements in mm.

N X SD CV MIN MAX

Endozone width 5 0.10 0.009 9.01 0.09 0.12

Exozone width 5 0.04 0.006 14.63 0.04 0.05

Mesotheca width 5 0.02 0 0 0.02 0.02

Aperture length 7 0.19 0.054 28.98 0.12 0.25

Aperture width 7 0.06 0.005 9.02 0.06 0.07

Aperture spacing across branch 4 0.19 0.018 9.77 0.17 0.21

Aperture spacing along branch 3 0.28 0.041 14.81 0.25 0.32

M. Zhang et al. / Palaeoworld 27 (2018) 343–359 357

References Chen, Z.L., Yu, J.H., Jin, S.Y., Bian, L.Z., Ju, T.Y., 1994. Classiﬁcation of reef

limestone in the Upper Ordovician Sanqushan Formation in the border area

between Zhejiang and Jiangxi provinces. Acta Micropalaeontologica Sinica

Anstey, R.L., Pachut, J.F., Tuckey, M.E., 2003. Patterns of bryozoan endemism

11 (1), 115–120 (in Chinese, with English abstract).

through the Ordovician–Silurian transition. Paleobiology 29 (3), 305–328.

Chen, Z.L., Yu, J.H., Jin, S.Y., Bian, L.Z., Ju, T.Y., 1995. Calcareous algae

Astrova, G.G., 1955. Mshanki. In: Ivanova, E.A., Soshikina, E.D., Astrova,

from Upper Ordovician Sanqushan Formation of Changshan, Zhejiang. Acta

G.G., Ivanova, V.A. (Eds.), Fauna ordovika i godandiya nizhnego techeniya

Micropalaeontologica Sinica 12 (2), 211–214 (in Chinese, with English

r. podkamennoj Tunguski, ee ekologiya i srratigraﬁcheskoe znachenie [Bry-

abstract).

ozoa: in Fauna of the Ordovician and Gotlandian of the lower reaches of the

Chen, Z.Y., Kim, M.H., Choh, S.J., Lee, D.J., Chen, X., 2015. Discovery of

Podkamennaya Tunguska River, its ecology and stratigraphic signiﬁcance].

Anticostia uniformis, from the Xiazhen Formation at Zhuzhai, South China

Trudy Paleontologischeskogo Instituta Akademiya Nauk SSSR 56, 128–161

and its stratigraphic implication. Palaeoworld 25 (3), 356–361.

(in Russian).

Conti, S., 1990. Upper Ordovician Bryozoa from Sardinia. Palaeontographica

Astrova, G.G., 1964. O novom otryade paleozojskikh mshanok [A new order of

Italica 77, 85–165.

Paleozoic Bryozoa]. Paleontologicheskii Zhurnal 2, 22–31 (in Russian).

Dai, M.J., Liu, L., Lee, D.J., Peng, Y.B., Miao, A.S., 2015. Morphometrics

Astrova, G.G., 1965. Morfologiya, istoriya razvitiya i sistema ordovikskikh i

of Heliolites (Tabulata) from the Late Ordovician, Yushan, Jiangxi, South

silurijskikh mshanok [Morphology, history of development and system of

China. Acta Geologica Sinica 89 (1), 38–54.

the Ordovician and Silurian Bryozoa]. Trudy Paleontologicheskogo Instituta

Dana, J.D., 1846. Zoophytes. United States Exploring Expedition 7, 1–740.

Akademii Nauk SSSR 106, 1–432 (in Russian).

Duncan, H., 1939. Trepostomatous Bryozoa from the Traverse Group of Michi-

Astrova, G.G., 1978. Istoriya razvitiya, sistema i ﬁlogeniya mshanok [Historical

gan. Contributions from the Museum of Paleontology 5 (10), 171–270.

development, systematics and phylogeny of Bryozoa. Order Trepostomata].

Ehrenberg, C.G., 1831. Symbolae Physicae, seu Icones et descriptions Cor-

Trudy Paleontologicheskogo Instituta Akademii Nauk SSSR 169, 1–240 (in

Russian). porum Naturalium novorum aut minus cognitorum, quae ex itineribusper

Libyam, Aegiptum, Nubiam, Dongalam, Syriam, Arabiam et Habessinian,

Astrova, G.G., Morozova, I.P., 1956. K sistematike mshanok otryada Cryp-

studia annis 1820–25, redirent. Pars Zoologica, 4. Animalia Evertebrata

tostomata [Systematics of Bryozoa of the order Cryptostomata]. Doklady

exclusis Insectis. Decus Primula, Berlin, 126 pp.

Akademii Nauk SSSR 110, 661–664 (in Russian).

Eichwald, E., 1855. Beitrag zur geographischen Verbreitung der fossilen Tiere

Bassler, R.S., 1903. The structural features of the bryozoan genus Homotrypa,

Russlands. Bulletin de la Sociétédes Naturelles de Moscovian 28, 433–466.

with descriptions of species from the Cincinnatian Group. U.S. National

Ernst, A., in press. Diversity dynamics of Ordovician bryozoa. Lethaia,

Museum Proceedings 26 (1323), 565–591.

https://doi.org/10.1111/let.12235.

Bassler, R.S., 1953. Bryozoa. In: Moore, R.C. (Ed.), Treatise on Invertebrate

Ernst, A., Carrera, M., 2012. Upper Ordovician (Sandbian) Bryozoan Fauna

Paleontology, Part G. Geological Society of America and University of

from Argentine Precordillera. Journal of Paleontology 86 (5), 721–752.

Kansas Press, New York and Lawrence, pp. 90–147.

Ernst, A., Key, M., 2007. Upper Ordovician Bryozoa from the Montagne de

Bian, L.Z., Fang, Y.T., Huang, Z.C., 1996. On the types of Late Ordovician reefs

Noire, southern France. Journal of Systematic Palaeontology 5 (4), 359–428.

and their characteristics in the neighbouring region of Zhejiang and Jiangxi

Fan, J.C., Hu, Z.X., 1990. Bryozoa. In: Southern Xinjiang Petroleum Prospect-

provinces, South China. In: Fan, J.S. (Ed.), The Ancient Organic Reefs of

ing Corporation and Xinjiang Petroleum Administration Bureau, Institute

China and Their Relation to Oil and Gas. Ocean Publication House, Beijing,

of Petroleum Geological Sciences, Yunnan–Guizhou–Guangxi Petroleum

pp. 54–75 (in Chinese).

Prospecting Bureau (Eds.), Stratigraphy and Palaeontology of Oil and Gas

Billings, E., 1865. Palaeozoic fossils, Vol. 1; containing descriptions and ﬁgures

Areas in China: Sinian to Permian Stratigraphy and Palaeontology of Tarim

of new or little known species of organic remains from the Silurian rocks.

Basin, Xinjiang (I): Kuruktag Region. Nanjing University Press, Nanjing,

Geological Survey of Canada 426, 54–55.

pp. 160–163, 234, 235 (in Chinese, with English abstract).

Billings, E., 1866. Catalogue of the Silurian fossils of the island of Anticosti,

Fang, Y.T., Bian, L.Z., Shi, G.J., Yu, J.L., Chen, M.J., Yu, J.H., 1993. Patch

with descriptions of some new genera and species. Geological Survey of

reefs and their communities of Late Ordovician Sangqushan Formation at

Canada 427, 1–93.

Wangjiaba, Yushan County, Jiangxi Province. Journal of Nanjing University

Blake, D.B., 1983. Systematic descriptions for the Suborder Rhabdomesina. In:

4, 670–679 (in Chinese, with English abstract).

Robison, R.A. (Ed.), Treatise on Invertebrate Paleontology, Part G: Bryozoa

Gorjunova, R.V., Lavrentjeva, V.D., 1993. Morfologiya i sistema kriptosto-

(Revised). Geological Society of America and University of Kansas Press,

midnykh mshanok [Morphology and systematics of the Cryptostome

Boulder and Lawrence, pp. 550–592.

bryozoans]. Trudy Paleontologicheskogo Instituta Rossiiskoi Akademii

Borg, F., 1926. Studies on recent cyclostomatous Bryozoa. Zoologiska Bidrag

Nauk 257, 1–152 (in Russian).

fran Uppsala 10, 181–507.

Hall, J., 1847. Organic remains of the lower division of the New York system

Buttler, C.J., Wyse Jackson, P.N., Ernst, A., McKinney, F.K., 2013. A review of

(equivalent of the Silurian Rocks of Europe). Natural History of New York,

the Early Palaeozoic biogeography of bryozoans. Memoirs of the Geological

Part 6, Palaeontology of New York 1, 1–338.

Society of London 38 (1), 145–155.

Hall, J., 1852. Organic remains of the lower middle division of the New York

Chang, X.L., Yang, H.J., Ding, X., Wu, Y.S., 2011a. Trepostome bryozoans in

system. Natural History of New York, Part 6, Palaeontology of New York 2,

the cores from the Lianglitag Formation (Upper Ordovician), central Tarim

1–362.

Basin, Xinjiang, China. Acta Micropalaeontologica Sinica 28 (2), 204–220

Hammer, Ø., Harper, D.A.T., Ryan, P.D., 2001. PAST: paleontological statistics

(in Chinese, with English abstract).

software package for education and data analysis. Palaeontologia Electronica

Chang, X.L., Yang, H.J., Yang, Z.L., Ding, X., Wu, Y.S., 2011b. Bryozoans

4 (1), 9.

(Cystoporida, Cryptostomida and Fenestrida) from the cores of the Lian-

Hu, Z.X., 1986a. Late Ordovician bryozoans from Yushan County, Jiangxi

glitag Formation (Upper Ordovician) in the central and northern Tarim Basin,

Province. Acta Micropalaeontologica Sinica 8 (2), 167–183 (in Chinese,

Xinjiang, NW China. Acta Micropalaeontologica Sinica 26 (1), 22–33 (in

with English abstract).

Chinese, with English abstract).

Hu, Z.X., 1986b. Some Trepostomatous Bryozoa from Upper Ordovician and

Chen, X., Rong, J.Y., Qiu, J.Y., Han, N.R., Li, L.Z., Li, S.J., 1987. Preliminary

Lower Devonian of Xainza, Xizang. Bulletin of Nanjing Institute of Geology

investigation of the Late Ordovician strata of Zhuzhai in Yushan of Jiangxi,

and Palaeontology, Academia Sinica 10, 195–200 (in Chinese, with English

their depositional features and environment. Journal of Stratigraphy 11 (1),

abstract).

23–34 (in Chinese, with English abstract).

James, U.P., 1884. Descriptions of four new species of fossils from the Cincinnati

Chen, X.S., 1996. Patch reef of Late Ordovician stromatoporoids and corals in

Group. The Journal of the Cincinnati Society of Natural History 7, 137–140.

Yushan, Jiangxi. Oil and Gas Geology 17 (4), 326–332 (in Chinese, with

Jiménez-Sánchez, A., Villas, E., 2010. The bryozoan dispersion into the

English abstract).

Mediterranean margin of Gondwana during the pre-glacial Late Ordovician.

Palaeogeography, Palaeoclimatology, Palaeoecology 294 (3), 220–231.

358 M. Zhang et al. / Palaeoworld 27 (2018) 343–359

Jiménez-Sánchez, A., Vennin, E., Villas, E., 2015a. Trepostomate bryozoans Nickles, J.M., Bassler, R.S., 1900. A synopsis of American fossil Bryozoa,

from the upper Katian (Upper Ordovician) of Morocco: gigantism in high including bibliography and synonymy. U.S. Geological Survey Bulletin 173,

latitude Gondwana platforms. Journal of Paleontology 89, 195–221. 1–663.

Jiménez-Sánchez, A., Villas, E., Vennin, E., 2015b. New trepostomate bryozoans Rominger, C., 1866. Observations on Chaetetes and some related genera, in

from the Upper Ordovician of Morocco and the temperature inﬂuence on regard to their systematic position; with an appended description of some new

zooid size. Journal of Paleontology 89, 385–404. species. Proceedings of the Academy of Natural Sciences of Philadelphia

Jiménez-Sánchez, A., Ernst, A., Vennin, E., Villas, E., 2016. New bryozoans 18, 113–123.

from the Upper Ordovician of Morocco and their place in the temperate-to- Rong, J.Y., Chen, X., 1987. Faunal differentiation, biofacies and lithofacies

cool water Mediterranean Province. Bulletin of Geosciences 91 (1), 23–50. pattern of Late Ordovician (Ashgillian) in South China. Acta Palaeontologica

Karklins, O.L., 1983. Systematic descriptions for the Suborder Ptilodictyina. In: Sinica 26 (5), 507–535 (in Chinese, with English introduction).

Robison, R.A. (Ed.), Treatise on Invertebrate Paleontology, Part G: Bryozoa Ross, J.R.P., 1960. Larger Cryptostome Bryozoa of the Ordovician and Silurian,

(Revised). Geological Society of America and University of Kansas Press, Anticosti Island, Canada: Part I. Journal of Paleontology 34 (6), 1057–1076.

Boulder and Lawrence, pp. 489–529. Ross, J.R.P., 1963. Constellaria from the Chazyan (Ordovician), Isle La Motte,

Kwon, S.W., Park, J., Choh, S.J., Lee, D.C., Lee, D.J., 2012. Tetradiid–siliceous Vermont. Journal of Paleontology 37 (1), 51–56.

sponge patch reefs from the Xiazhen Formation (late Katian), southeast Ross, J.R.P., 1964. Champlainian Cryptostome Bryozoa from New York State.

China: a new Late Ordovician reef association. Sedimentary Geology Journal of Paleontology 38 (1), 1–32.

267–268 (4), 15–24. Ross, J.R.P., 1970. Distribution, paleoecology and correlation of Champlainian

Lavrentjeva, V.D., 1979. Phylloporinina — novyj podotrâd paleozojskih msanokˇ Ectoprocta (Bryozoa), New York State, Part III. Journal of Paleontology 44

[Phylloporinina — a new suborder of Palaeozoic Bryozoa]. Paleontologich- (2), 346–382.

eskii Zhurnal 1, 59–68 (in Russian). Ross, J.R.P., 1985. Biogeography of Ordovician ectoproct (bryozoan) faunas.

Lee, D.C., 2013. Late Ordovician trilobites from the Xiazhen Formation in In: Nielsen, C., Larwood, G.P. (Eds.), Bryozoa: Ordovician to Recent. Olsen

Zhuzhai, Jiangxi Province, China. Acta Palaeontologica Polonica 58 (4), and Olsen, Fredensborg, Denmark, pp. 265–272.

855–882. Ross, J.R.P., Ross, C.A., 2007. Ordovician bryozoans and sequence stratigraphy

Lee, D.C., Park, J., Woo, J., Kwon, Y.K., Lee, J.G., Guan, L.M., Sun, N., in Tasmania. Memoirs of the Association of Australasian Palaeontologists

Lee, S.B., Liang, K., Liu, L., Rhee, C.W., Choh, S.J., Kim, B.S., Lee, D.J., 34, 197–226.

2012. Revised stratigraphy of the Xiazhen Formation (Upper Ordovician) Schulga-Nesterenko, M.I., 1955. Kamennougolnye mshanki Russkoi Platformy

at Zhuzhai, South China, based on palaeontological and lithological data. [Carboniferous Bryozoa of the Russian Platform]. Trudy Paleontologich-

Alcheringa 36 (3), 1–20. eskogo Instituta Akademii Nauk SSSR 57, 1–157 (in Russian).

Lee, M., Elias, R.J., Choh, S.J., Lee, D.C., 2016. Insight from early Sun, N., Elias, R.J., Choh, S.J., Lee, D.C., Wang, X.L., Lee, D.C., 2016. Mor-

coral–stromatoporoid intergrowth, Late Ordovician of China. Palaeogeog- phometrics and palaeoecology of the coral Agetolites from the Xiazhen

raphy, Palaeoclimatology, Palaeoecology 463, 192–204. Formation (Upper Ordovician), Zhuzhai, South China. Alcheringa 40 (2),

Li, Q.J., Li, Y., Kiessling, W., 2015. Allogenic succession in Late Ordovician 1–24.

reefs from southeast China: a response to the Cathaysian orogeny. Estonian Suttner, T.J., Ernst, A., 2007. Upper Ordovician bryozoans of the Pin Formation

Journal of Earth Sciences 64 (1), 68–73. (Spiti valley, northern India). Palaeontology 50 (6), 1485–1518.

Liang, K., Elias, R.J., Choh, S.J., Lee, D.C., Lee, D.J., 2016. Morphometrics Taylor, P.D., Ernst, A., 2004. Bryozoan diversiﬁcation during the Ordovician.

and paleoecology of Catenipora (Tabulata) from the Xiazhen Formation In: Webby, B.D., Paris, F., Droser, M.L., Percival, I.G. (Eds.), The Great

(Upper Ordovician), Zhuzhai, South China. Journal of Paleontology 90 (6), Ordovician Biodiversiﬁcation Event. Columbia University Press, New York,

1027–1048. pp. 147–156.

Liu, X.L., 1980. Bryozoa. In: Shenyang Institute of Geology and Mineral Tuckey, M.E., 1990. Biogeography of Ordovician bryozoans. Palaeogeography,

Resources (Ed.), Paleontological Atlas of Northeast China: Paleozoic, Part Palaeoclimatology, Palaeoecology 77 (2), 91–126.

1, Paleozoic Volume. Geological Publishing House, Beijing, pp. 189–254, Ulrich, E.O., 1882. American Palaeozoic Bryozoa. The Journal of the Cincinnati

649–654 (in Chinese). Society of Natural History 5, 121–175, 233–257.

Liu, X.L., 1987. Ordovician bryozoans from Da Hingan Ling in Northeast China. Ulrich, E.O., 1888. On Sceptopora, a new genus of Bryozoa, with remarks

In: Papers of Stratigraphy and Palaeontology 17. Geological Publishing on Helopora Hall, and other genera of that type. American Geologist 1,

House, Beijing, pp. 197–213 (in Chinese, with English abstract). 228–234.

Lonsdale, W., 1839. Corals. In: Murchison, R.I. (Ed.), The Silurian System. Part Ulrich, E.O., 1893. On Lower Silurian Bryozoa of Minnesota. The Geological

2. Organic Remains. John Murray, London, pp. 675–694. and Natural History Survey of Minnesota, Final Report 3, 96–332.

Lu, Y.H., Chu, Z.L., Qian, Y.Y., Zhou, Z.Y., Chen, J.Y., Liu, G.W., Yu, W., Ulrich, E.O., 1896. Bryozoa. In: Eastman, C. (Ed.), Zittel’s Textbook of Palaeon-

Chen, X., Xu, H.K., 1976. Ordovician biostratigraphy and palaeozoogeog- tology, Vol. 1. Macmillan, London, pp. 257–291.

raphy of China. Memoirs of Nanjing Institute of Geology and Palaeontology, Ulrich, E.O., Bassler, R.S., 1904. A revision of the Palaeozoic Bryozoa. Part

Academia Sinica 7, 1–83 (in Chinese). II. On genera and species of Trepostomata. Bulletin of the US Geological

Ma, J.Y., Buttler, C.J., Taylor, P.D., 2014. Cladistic analysis of the ‘trepostome’ Survey 173, 15–55.

Suborder Esthonioporina and the systematic of Palaeozoic bryozoans. Studi Vine, G.R., 1884. Fourth report of the Committee consisting of Dr. H.R. Sorby

Trentini di Scienze Naturali 94, 153–161. and Mr. G.R. Vine, appointed for the purpose of reporting on fossil Polyzoa.

Ma, J.Y., Taylor, P.D., Xia, F.S., Zhan, R.B., 2015. The oldest known bryozoan: Reports of the 53rd Meeting of the British Association for the Advancement

Prophyllodictya (Cryptostomata) from the Lower Tremadocian (Lower in Sciences, pp. 161–209.

Ordovician) of Liujiachang, South-western Hubei, Central China. Palaeon- Xia, F.S., Zhang, S.G., Wang, Z.Z., 2007. The oldest bryozoans: new evidence

tology 58 (5), 925–934. from the Late Tremadocian (Early Ordovician) of East Yangtze Gorges in

Miller, S.A., 1889. North American Geology and Paleontology. Western China. Journal of Paleontology 81 (6), 1308–1326.

Methodist Book Concern, Cinncinnati, 664 pp. Xia, F.S., Ma, J.Y., Hao, J.S., 2010. Ordovician bryozoan diversity changes

Nicholson, H.A., 1881. On the Structure and Afﬁninties of the Genus Montic- and bearing on the origin of bryozoa. Acta Palaeontologica Sinica 49 (2),

ulipora and Its Subgenera with Critical Descriptions of Illustrative Species. 139–163 (in Chinese, with English abstract).

William Blackwood and Sons, Edinburgh, 235 pp. Yang, J.Z., Hu, Z.X., 1962. Bryozoans of China. Science Press, Beijing, 89 pp.

Nicholson, H.A., Etheridge, R., 1877. On Prasopora grayae, a new genus (in Chinese).

and species of Silurian corals. Annals and Magazine of Natural History Yang, J.Z., Lu, L.H., 1962. Paleozoic bryozoans of Qilian Mountains. Geology

4, 388–392. of Qilian Mountains 4 (5), 51 (in Chinese).

M. Zhang et al. / Palaeoworld 27 (2018) 343–359 359

Yang, J.Z., Lu, L.H., Zhou, G.D., 1979. Bryozoa. In: Nanjing Institute of Geol- Zhan, R.B., Jin, J.S., Liu, J.B., 2013. Investigation on the great Ordovician biodi-

ogy and Palaeontology (Ed.), Atlas of Palaeontology from Northwest China versiﬁcation event (GOBE): review and prospect. Chinese Science Bulletin

(Qinghai), Part 2. Geological Publishing House, Beijing, p. 66 (in Chinese). 58 (33), 3357–3371 (in Chinese, with English abstract).

Zhan, R.B., Fu, L.P., 1994. New observations on the Upper Ordovician stratigra- Zhang, F., 2016. Recognizing morphospecies in the heliolitid coral Plasmo-

phy of the Zhejiang–Jiangxi border region, E China. Journal of Stratigraphy porella. Palaeoworld 25 (1), 32–42.

18, 267–274 (in Chinese, with English abstract). Zhang, Y.D., Chen, X., Yu, G.H., Goldman, D., Liu, X., 2007. Ordovician and

Zhan, R.B., Jin, J.S., 2007. Ordovician–Early Silurian (Llandovery) Stratigraphy Silurian Rocks of Northwest Zhejiang and Northeast Jiangxi Provinces SE

and Palaeontology of the Upper Yangtze Platform, South China. Science China. University of Science and Technology of China Press, Hefei, 189 pp.

Press, Beijing, 169 pp. Zheng, Y.J., 1989. Ordovician Bryozoans from Nei Mongol–Hinggan Ling

Zhan, R.B., Rong, J.Y., 1995. Distribution pattern of Late Ordovician brachio- Range. Bulletin of Shenyang Institute of Geology and Mineral Resources,

pod communities in the Zhejiang–Jiangxi border region. Chinese Science Chinese Academy of Geological Sciences 19, 61–71 (in Chinese, with

Bulletin 40, 932–935 (in Chinese, with English abstract). English abstract).

Zhan, R.B., Rong, J.Y., Jin, J.S., Cocks, L.R.M., 2002. Late Ordovician brachio- Zittel, K.A., 1880. Handbuch der Palaeontologie. Abteilung 5. Palaeozoologie,

pod communities of southeastern China. Canadian Journal of Earth Sciences Vol. 1. Oldenbourg, München, 765 pp.

39 (4), 445–468.