Paleoecology of a Pennsylvanian Encrusting Colonial Rugose Coral in South Guizhou, China

Palaeogeography, Palaeoclimatology, Palaeoecology 280 (2009) 507–516

Contents lists available at ScienceDirect

Palaeogeography, Palaeoclimatology, Palaeoecology

journal homepage: www.elsevier.com/locate/palaeo

Paleoecology of a Pennsylvanian encrusting colonial rugose coral in south Guizhou, China

Yong-li Zhang a, En-pu Gong a,⁎, Mark A. Wilson b, Chang-qing Guan a, Bao-liang Sun a, Hong-lun Chang a a Department of Geology, Northeastern University, Shenyang, 110004, PR China b Department of Geology, The College of Wooster, Wooster, OH 44691, USA article info abstract

Article history: The well-preserved Pennsylvanian encrusting colonial rugose coral Ivanovia is widespread and easily Received 4 February 2009 observed in south Guizhou, China. There are three common types of hard substrate encrusted by Ivanovia: in Received in revised form 20 June 2009 situ carbonate hardgrounds, carbonate hardground clasts, and calcareous bioclasts. Thin, spreading sheets are Accepted 1 July 2009 the most common growth form of Ivanovia in the study region. Ivanovia employed peripheral, medial and Available online 30 July 2009 mixed growth strategies to occupy a sufﬁcient living space on the substrate. It favored a shallow, warm, and clear marine environment within the photic zone and had a high tolerance of water movement. Ivanovia was Keywords: generally smothered and covered by mud in the studied area. The Ivanovia fossil communities in south Hard substrate Encrusting Guizhou are characterized by a low species diversity conforming to the typical evolutionary pattern of hard Colonial rugose coral substrate marine communities in the Carboniferous. Paleoecology © 2009 Elsevier B.V. All rights reserved. Pennsylvanian South Guizhou

1. Introduction Lescinsky, 1997; Nakazawa, 2001). More work is necessary to better delineate the diversity pattern of hard substrate communities in the Until recently, encrusting metazoans were reported as relatively geologic record, so we need detailed studies of encrusting assem- rare on hard substrates in the Carboniferous (Alvarez and Taylor, 1987; blages in the Carboniferous (Brett, 1988; Taylor and Wilson, 2003). Brett, 1988; Lescinsky, 1997; Sumrall et al., 2006; Wilson and Palmer, The present study focuses on well-preserved examples of the 1992). In the Paleozoic, much of the increased abundance and Pennsylvanian encrusting colonial rugose coral Ivanovia. Specimens of diversity of hard substrate communities was mainly due to the this coral are widespread and easily studied in south Guizhou, China increase in hard substrate availability (Palmer, 1982; Wilson et al., (Guan et al., 2006). Encrusters are generally preserved in situ, 1989; Wilson et al., 1992; Wilson and Palmer, 1992; Taylor and Wilson, retaining their original positions on the substrate and thus offering 2003). Carbonate hardgrounds were rare in the Carboniferous (Suchy important advantages for a paleoecological study. The purpose of this and West, 1988; Wilson and Palmer, 1992; Taylor and Wilson, 2003) paper is to study the habit, growth forms and ecology of Ivanovia.It and thus the hard substrate niche was relatively uncommon at this provides a new example for the study of encrusting organisms on hard time. It is possible that the environmental stresses provided a selective substrates of the Carboniferous. pressure favoring marine benthic organisms which did not require hard substrates. In general, the low-diversity Carboniferous hard 2. Setting and stratigraphy substrate communities may have been overlooked because few ﬁ workers expect to nd them (Lescinsky, 1994; Lescinsky, 1997). South Guizhou, southern China, is characterized by extended Although carbonate hardgrounds seem to be rare in the Carboniferous, outcrops of Carboniferous and Permian carbonate rocks. There are some other types of hard substrate such as calcitic skeletons, shells abundant fossils in these rocks, thus the region has been a focus of and mobile rocks are abundant. Studies of Carboniferous inorganic Carboniferous stratigraphy and paleontology (Wu, 1987; Li et al.,1996; hard substrates are thus surprisingly few (Palmer, 1982; Edwards and Liu et al., 1994; Feng et al., 1999; Jin et al., 2000; Wang and Qi, 2002; Marcus, 1993; Webb, 1993), but the encrusting taxa on organic hard Zhang, 2002). The Houchang region, south Guizhou, lies on the substrates are relatively well known from this interval (Taylor, 1985; southern margin of the Yangtze Plate, with its strata belonging to the Cossey and Mundy, 1990; Powers and Ausich, 1990; Molineux, 1994; Yunnan–Guizhou–Guangxi subregion of south China and southern Guizhou, northern Guangxi and southeastern Yunnan areas (Wang et al., 1990). Strata of Carboniferous to Permian age in this region are ⁎ Corresponding author. Tel.: +86 24 83675066; fax: +86 24 83689266. E-mail addresses: [email protected] (Y. Zhang), [email protected] (E. Gong), mostly light grey, medium- to thick-bedded and massive limestones [email protected] (M.A. Wilson). representative of shallow epicontinental sea deposits (Wu, 1987;

Fig. 1. (A) Location of the studied area west of Houchang, south Guizhou Province, China. (B) A geological map of the study area. Y. Zhang et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 280 (2009) 507–516 509

GGMRB, 1987). The Carboniferous sequences consist of the fossilifer- high and about 10 cm long, was found on a fusulinid grainstone ous Weining and Maping formations (GGMRB, 1987). In the substrate (Fig. 4E). Pennsylvanian, this region was on the high-energy margin of a carbonate platform with many reefal buildups (Fan and Rigby, 1994; 4. Types of hard substrate encrusted by Ivanovia Guan et al., 2004; Gong et al., 2004; Guan et al., 2006, 2007; Sun et al., 2007; Gong et al., 2007a,b,c; Zhang et al., 2007). 4.1. Carbonate hardgrounds (in situ) The colonial rugose coral Ivanovia is abundant near the village of Bianping, about 4 km west of Houchang, Ziyun County, in Guizhou Hardgrounds are synsedimentarily lithified seafloors formed by Province (Fig. 1). It is found in a thick, cyclic sequence of bedded and precipitation of carbonate cements in primary pore spaces (Wilson massive Pennsylvanian and Permian limestones which also contain and Palmer, 1992). The substrate of Ivanovia in this study consists of large numbers of other benthic organisms such as fusulinids, corals, bioclastic grainstone with common fragments of fusulinids, crinoids and brachiopods. Ivanovia occurs in the Triticites Zone of the Maping and brachiopods, and of boundstone. The primary pore spaces Formation (uppermost Pennsylvanian) (Fig. 2)(Guan et al., 2006). between skeletal grains are filled with synsedimentary marine The common fusulinids include: Triticites pygmaeus, T. simplex, T. cements (botryoidal, isopachous and fibrous) (Fig. 5A, B and C). parvus, T. minimus, T. chinensis, T. subrhomboides, Schwagerina vul- Cement crusts (multi-generations of syndepositional calcite cement) garis, S. subnathorsti, S. kuenchinensis, and S. amushanensis (Ding are mainly developed in the larger cavities (Fig. 5D). The synsedi- et al., 1992). Brachiopods (Choristites sp., Squamularia sp., Echinaria mentary cements represent over 20–30% of the rock volume of the sp., Wellerella sp., Martinia sp.) and corals (Caninia sp., Fomitchevella substrate colonized by Ivanovia. Generally Ivanovia grew by following sp., Antheria sp., Ivanovia sp.) are also common in this sequence (Li the shape of the substrate, demonstrating that it was initiated on the and Zhao, 1993; Zhang, 2002). hardground after cementation (Fig. 5E). Tubiphytes is relatively abundant in the substrate underlying Iva- novia. Tubiphytes is generally considered to have been a binding 3. Morphology and growth forms of Ivanovia organism, but it also seems to have functioned as framework constructor (Riding and Guo, 1992; Senowbari-Daryan and Flügel, Ivanovia is a massive aphroid coral (Fig. 3). The corallites are 1993; Wang et al., 1994; Wang et al., 1998; Tian and Fan, 2001; Shen connected with cystosa. Major septa are long, with their bases and Xu, 2005). In the study region, Ivanovia occasionally colonized disrupted by cystosepiments; they rarely reach the columella. Minor Tubiphytes boundstone. Tubiphytes is often associated with bioclasts septa are occasionally developed. The columella is a thin plate or cemented by synsedimentary cement in the substrate underneath fusuliform. Tabulae lightly incline toward the center. The internal Ivanovia (Fig. 6). Tubiphytes boundstone contains some tubular structural organization of Ivanovia is aphroid (Fig. 3A); the astogeny of structures filled with calcite lacking any internal features, suggesting this coral involves a form of non-parricidal budding (Scrutton, 1998). that they may be borings. Thin, spreading sheets are the most common growth form of Ivanovia In the study region, the outcrops with Ivanovia encrusting the in the study region (Fig. 4A). These colonies generally are 2–10 cm carbonate hardgrounds have a lateral extent of 1–10 m. The Ivanovia thick and 1–10 m long. Ivanovia also has both spreading tabular and beds are discontinuous so that none of the hardgrounds encrusted by domal growth forms with a maximum colony thickness of 30–40 cm Ivanovia forms continuous, unbroken platforms; they are all con- (Fig. 4B). Occasionally, thin, spreading sheets, which grew closely siderably localized. A depositional environment at the seaward juxtaposed near and above one another occur (Fig. 4C and D). The new platform margin with high water energy was assumed for the study colonies were established by offshoots from surviving older polyps region (GGMRB, 1987; Fan and Rigby, 1994; Gong et al., 2004). The (Fig. 4D). In addition, a mini-domal growth form of Ivanovia,4–5cm ubiquitous synsedimentary marine cements indicate significant

Fig. 2. Stratigraphic scheme of Upper Pennsylvanian and Lower Permian rocks in the study area based on fusulinid and coral assemblages. The dark star indicates the stratigraphic position of Ivanovia. 510 Y. Zhang et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 280 (2009) 507–516

Fig. 3. (A) Polished slab showing a longitudinal section of Ivanovia. The corallites are connected with cystosa; the internal structures are aphroid. (B) Cross-sections of Ivanovia on a weathered limestone surface. (C) Photomicrographs of a longitudinal section of Ivanovia. (D) Photomicrographs of a cross-section of an Ivanovia corallite. seawater circulation under open, normal-marine conditions. Sea-level proportion of the colony remained present on the upright portion of changes of the Triticites zone were frequent during the Pennsylvanian the rock so it could continuously encrust the newly exposed surface. (Liu et al., 1994; Li et al., 1996). The frequent changes of sea-level and Ivanovia often completely encrusted the clasts. strong energy may have often eroded away carbonate hardgrounds. Furthermore, the seawater of the Carboniferous was characterized by 4.3. Calcareous bioclasts high-magnesium calcite and inorganic aragonite precipitation (an ‘Aragonite Sea’). Aragonite Sea conditions do not favor widespread Calcareous bioclasts also provided hard substrates for Ivanovia. formation of carbonate hardgrounds (Wilson and Palmer, 1992; Taylor These clasts, which range from pebble- to cobble-size, are derived and Wilson, 2003). from animals with robust calcareous skeletons. The most common are clusters of brachiopods, followed by colonies of Ivanovia. Some spaces 4.2. Carbonate hardground clasts between the shells are filled with several generations of syndepositional calcite cement. This cement made the clusters of shells into Many carbonate hardground fragments encrusted by Ivanovia are stable substrates for Ivanovia. Ivanovia also encrusted aragonitic shells found in the study area. These intraclasts, which range from pebble- to which were replaced by sparry calcite, leaving casts (Fig. 7). cobble-size, vary in shape and are mainly composed of mud or Occasionally its colony surrounded the whole shell and then bioclasts with marine cements. There are no lithologic or biotic continuously grew onto the surrounding sediment substrate. Gen- differences between the hardground fragments mainly composed of erally, the colony of Ivanovia is thin when encrusting a single bioclasts and the surrounding matrix. They were locally derived from calcareous clast. This may be a result of the clast frequently hardgrounds that were broken up on the sea floor by storm and wave overturning in the high-energy environment (Wilson, 1987). action. The hardground fragments composed of mud appear to have Along with the above three types of hard substrate, microbial been derived from broken-up mudstone. The angular and subangular carbonate also provided hard substrate for Ivanovia.Microbial mud fragments were not transported far before final deposition. carbonates are boundstones with internal laminations characterized The hardground clasts provided mobile hard substrates for Ivano- by alternation of crinkled couplets. The couplets are laterally via. These clasts were mobile rocks which were potentially valuable continuous laminae that encrust the substrate and bind the sediment. resources for encrusting and boring organisms (Wilson, 1987). The Their growth model is the same as for a stromatolite (Riding, 1999; clasts were overturned in the high-energy environments, smothering Shapiro, 2002; Shen and Xu, 2005; Riding, 2006). In this case, the and burying any encrusting colonies of Ivanovia encrusted to them. colony size of Ivanovia is generally small which may be due to the Occasionally Ivanovia survived overturning events if a significant overgrowth of Ivanovia by microbial mats. Y. Zhang et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 280 (2009) 507–516 511

Fig. 4. Growth-forms of Ivanovia.(A–B) Thin, spreading sheets. (C) Field view of the thin, spreading sheets, growing closely juxtaposed near and above one another. (D) Field view of new colony established by offshoots from surviving polyps (white rectangle). (E) A mini-domal growth form of Ivanovia on a grainstone substrate characterized by abundant fusulinids (white arrow).

5. Paleoecology of Ivanovia order to survive and reproduce may be very different. Encrusting colonial metazoans generally cover extensive areas of hard substrates 5.1. Colonial growth strategy of Ivanovia by colonial propagation (Wood, 1995). In the study area, Ivanovia employed different growth strategies to occupy a sufficient living Living space is often at a premium for sessile benthic organisms on space on the substrate. The flatter, spreading growth form of Ivanovia hard substrates (Taylor and Wilson, 2003). The strategies employed by is a result of a peripheral growth strategy (Fig. 8B). This strategy sessile benthic organisms to secure a sufficient area of substrate in resulted in the rapid lateral spread of a colony across the hard 512 Y. Zhang et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 280 (2009) 507–516

Fig. 5. (A) Photomicrograph of bioclastic grainstone. Fusulinids (F) are common and the primary pore spaces between skeletal grains are filled with radiaxial fibrous cements (RFC). (B) Photomicrograph of bioclastic grainstone. The bioclasts are encrusted by isopachous cement (white arrow) prior to the precipitation of radiaxial fibrous cement (RFC)in interstitial space. Tubiphytes (T) encrust a bryozoan fragment (Br). (C) Botryoidal cement (BC) growing on fusulinid fragments (F). (D) Polished slab showing the large space between the skeletal fragments filled by cement crusts (Cc). The bioclasts are mainly brachiopods (B), crinoids (C) and Tubiphytes (white arrow). (E) Field view of Ivanovia encrusting the in situ carbonate hardgrounds. Ivanovia grew by following the shape of the substrate. The white arrow indicates the growth direction of Ivanovia. substrate surface to cover extensive areas. It was the most effective upward than lateral growth of the corallites (Fig. 8B). This strategy can strategy for Ivanovia to encrust non- or minimally aggrading hard cope with more continuous or higher rates of sediment accumulation substrates (Scrutton, 1998). The corallites of the peripheral growth are by predominantly upward growth (Scrutton, 1998). The thick, tabular, generally subparallel and all of a consistent orientation, upright in growth form of Ivanovia was constructed by a combination of most cases (Fig. 3A). The domal growth form of Ivanovia is usually peripheral and medial growth strategies. The colonies with a mixed associated with a medial growth strategy. Such colonies are generally strategy (Fig. 8B) are usually relative large in the study region. very small and domal. The medial strategy facilitates more rapid Individuals of Ivanovia employed a peripheral strategy to secure a Y. Zhang et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 280 (2009) 507–516 513

Fig. 6. Photomicrograph showing abundant Tubiphytes (T) associated with bioclasts cemented by isopachous cements (white arrow). Tubiphytes are columnar with central tubes. The walls of the tubes are dark and composed of microcrystalline calcite. The spaces between the bioclasts are ﬁlled with marine cements (Ce). Other fossils include gastropods (G) and fusulinids (F).

sufﬁcient area of substrate during their colonization stage. When the depositional environments changed, they employed the medial strategy to cope with the higher rate of sediment accumulation. Most Paleozoic corals died by burial in sediments (Scrutton, 1998). Ivanovia was generally smothered by mud in this study area (Fig. 8A) (Guan et al., 2006). The high sedimentation rate (bed load transport or deposition from suspension) could easily have smothered corallites around the colony margins or on the colony surface, resulting in partial or total mortality. A new laterally spreading colony of Ivanovia could have been re-established by offshoots from surviving polyps when sedimentation was intermittent or subsequently reworked by currents (Fig. 4C and D). Controls on colony size are complex, including the stability of the Fig. 8. (A) Polished slab showing muddy sediment covering an Ivanovia colony. (B) Sketch environment, substrate condition and frequency of sedimentation of growth strategies employed by Ivanovia: (1) peripheral, (2) medial and (3) mixed (not to scale). events. In the study region, the colonies of Ivanovia encrusting carbonate hardgrounds (in situ) are larger than those on other types of hard substrate. On the same hard substrate, colony size is associated

with the stability of the environment and frequency of sedimentation events. The colony size of Ivanovia encrusting the pebble- to cobble- sized mobile rocks or bioclasts was mainly controlled by the size of clasts and frequency of overturning.

5.2. Habitat of Ivanovia

In the Pennsylvanian, the study region was on the margin of a carbonate platform with high water energy and many bioclastic banks, phylloid algal mounds and a large coral reef (Gong et al., 2004, 2007a,c). Its sediments mainly consist of grayish, massive bioclastic limestones. Thick biogenic deposits with abundant skeletons of benthic organisms are an important indication of tropical and subtropical environments (Fan and Rigby, 1994; Guan et al., 2004; Gong et al., 2004, 2007a; Zhang et al., 2007). Hardgrounds are most common in tropical and subtropical shallow carbonate environments (Wilson and Palmer, 1992). South China was situated in low-latitudes during the Pennsylvanian (Scotese, 1997). Furthermore, paleomagnetism and sediments also indicate that south Guizhou Province was located in a low-latitude region at this time (Wang and Li, 1998). In addition, the ubiquitous synsedimentary marine Fig. 7. Ivanovia encrusting a calcareous shell which has some internal structures (white cements and abundant benthic organisms are also indicators of an open, arrow). Most of the calcareous shell is replaced by sparry calcite (Sc). normal-marine environment (Gong et al., 2007a). 514 Y. Zhang et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 280 (2009) 507–516

Tubiphytes is the most common organism associated with the Ivanovia was easily smothered and covered by sediments. Thus, they growth of Ivanovia, which favored shallow, warm, and clear sea water commonly formed thin colonies on the surface of mobile hard (Wang et al., 1994; Wang et al., 1998; Tian and Fan, 2001). The substrates. Ivanovia was apparently not adapted to a relatively quiet fossilization of Tubiphytes required sea water to be saturated with environment with high sedimentation rates. Their growth forms were calcium carbonate, and thus they can serve as an indicator of tropical generally mini-domal under this condition. The thin, spreading sheets, environment (Wang et al., 1994). The microbial carbonates encrusted growing closely juxtaposed near and above one another, are a by Ivanovia are especially common in intertidal and shallow subtidal reflection of frequent depositional environment changes. marine environments (Taylor and Wilson, 2003). The fossil assemblage of Ivanovia, microbial mats and Tubiphytes may point to a shallow water depositional environment within the photic zone. 5.3. Biodiversity and the Ivanovia community Massive Paleozoic colonial corals tended to live in shallow, higher energy environments, gaining stability from their weight (Scrutton, Due to its rapid lateral spreading growth, Ivanovia excluded most 1998). Li and Zhao (1993) studied the Pennsylvanian rugose corals of other shallow water hard substrate organisms. There are a few benthic Guizhou and suggested that the massive coral Ivanovia could have organisms in the community dominated by Ivanovia such as withstood high wave turbulence and that their colonies grew fusulinids, encrusting Tubiphytes, smaller foraminifers, and brachio- rapidly. Analyzing its functional morphology, the framework of Iva- pods. The low-diversity Ivanovia community conforms to the pattern novia could have withstood significant water energy. Under shallow, of hard substrate marine community evolution in the Carboniferous higher energy conditions, the growth forms and internal structures (Palmer, 1982; Brett, 1988; Wilson and Palmer, 1992; Webb, 1993; of Ivanovia were likely ecophenotypically influenced by ambient Taylor and Wilson, 2003). The frequent changes of depositional environments. The cystosa of Ivanovia were generally strong and environment and the scouring effects in high-energy environments large during the initial colonization stage (Fig. 9), which may may have affected the abundance and diversity of encrusting indicate the high water energy. The strong cystosa probably could organisms. Ivanovia favored shallow, high-energy environments have withstood strong currents and wave turbulence. The lateral where only some encrusting colonial organisms can cover extensive spreading tabular growth form could have increased substrate areas of hard substrates (Wilson, 1987). The hard substrate commu- acquisition and enhanced attachment efficiency of the colonies. nities dominated by Ivanovia were commonly covered by sediments The peripheral strategy employed by most colonies of Ivanovia in the following a rise in sea-level. study region also indicates low sedimentation rates and clear water Ivanovia occurs as a structural organism in the substrate of a large conditions (Scrutton, 1998). coral reef in the Pennsylvanian of the studied area (Guan et al., 2004; The substrate beneath Ivanovia is commonly bioclastic grainstone Gong et al., 2004, 2007c). Lateral spreading tabular growth forms of containing abundant fragments of fusulinids, brachiopods, crinoids Ivanovia are commonly found in the substrate of the coral reef. Their and bryozoans. The spaces between skeletal grains are filled with calcified skeletons provided a relatively stable habitat for the reef- synsedimentary marine cements. These sediments are commonly building coral Fomitchevella. In the substrate of the reef, some formed in shallow water environment with wave action where the pioneers of Fomitchevella were encrusted by the rapid-spreading Iva- sedimentation rates are low (Carozzi, 1989). The abundant Tubiphytes novia, probably forming a final bioclaustration (Fig. 10). Fomitchevella associated with Ivanovia can also indicate a depositional environment has a fasciculate growth form and its corallites are cylindrical, thick of shallow, clear and agitated marine water (Wang et al., 1994; Gong and long (Guan et al., 2004; Gong et al., 2004, 2007c). The framework and Fan, 2000). Occasional storm events probably killed colonies of of Fomitchevella may have been more stable when the corallites were Ivanovia. Many clasts of Ivanovia are found around the in situ colonies. accompanied by Ivanovia. On the sea floor, Fomitchevella were the When they were overturned, it likely resulted in the death of the high-tier microcarnivores and Ivanovia were the relatively low-tier colony as a whole. Mobile rocks and calcareous bioclasts are often microcarnivores. They likely lived together with a vertical and limited overturned in this kind of high-energy environment. In this condition, supply of nutrients (Scrutton, 1998).

Fig. 9. Polished slab showing the relatively strong and large cystosa (white rectangle)of Fig. 10. Field view of the pioneers of Fomitchevella (F) encrusted by the spreading Ivanovia near the substrate. Ivanovia, probably forming a ﬁnal bioclaustration. Y. Zhang et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 280 (2009) 507–516 515

6. Conclusions Gong, E.P., Samankassou, E., Guan, C.Q., Zhang, Y.L., Sun, B.L., 2007a. Paleoecology of Pennsylvanian phylloid algal buildups in south Guizhou, China. Facies 53, 615–623. Gong, E.P., Zhang, Y.L., Guan, C.Q., Samankassou, E., Sun, B.L., 2007b. Paleoecology of Late Carboniferous phylloid algae in Southern Guizhou, SW China. Acta Geologica Sinica 1) The well-preserved Pennsylvanian encrusting colonial rugose coral 81 (4), 566–572. Ivanovia is widespread and easily studied in south Guizhou, China. Gong, E.P., Zhang, Y.L., Guan, C.Q., Sun, B.L., 2007c. Primary features of reef-building It is a new example of an encrusting colonial metazoan on hard communities of Carboniferous reef in South Guizhou Province (in Chinese with – substrates in the Carboniferous. It is a good subject for studying the English abstract). Acta Geologica Sinica 81 (9), 1183 1194. Guan, C.Q., Gong, E.P., Yao, Y.Z., Sun, B.L., 2004. Biocoenose community analysis of evolution of encrusting organisms and paleoecology in the Bianping reefs of the Late Carboniferous in southern Guizhou Province (in Chinese Carboniferous. There were three common types of hard substrate with English abstract). Journal of Palaeogeography 6 (3), 339–346. encrusted by Ivanovia: in situ carbonate hardgrounds, carbonate Guan, C.Q., Gong, E.P., Zhang, Y.L., Sun, B.L., 2006. Palaeoecological characteristic of Ivanovia cf. manchurica coral and the reef mechanism of the Late-Carboniferous hardground clasts, and calcareous bioclasts. Microbial carbonate in the South of Guizhou Province (in Chinese with English abstract). Geological also provided hard substrate for Ivanovia. The seawater of the Review 52 (2), 178–183. Carboniferous was characterized by high-magnesium calcite and Guan, C.Q., Gong, E.P., Zhang, Y.L., Sun, B.L., Chen, H., Guo, J.H., Li, Q., 2007. A new type ‘ ’ reef of the Late Carboniferous in the South of Guizhou Province (in Chinese with inorganic precipitation of aragonite (an Aragonite Sea ) which did English abstract). Geological Review 53 (4), 433–439. not favor rapid and widespread formation of carbonate hard- Jin,Y.G.,Fan,Y.N.,Wang,X.D.(Eds.),2000.ChineseStratigraphyLexicon(Carboniferous grounds. However, most hardgrounds today are cemented by System) (in Chinese with English abstract). Geological Publishing House, Beijing, p. 189. Lescinsky, H.L., 1994. The Late Devonian extinction: effects on shell encrusting aragonite (Taylor and Wilson, 2003). Thus, we need detailed communities. Paleobios 16 (Suppl. 1), 9–10. studies of carbonate hardground formation in the Carboniferous. Lescinsky, H.L., 1997. Epibiont communities: recruitment and competition on North 2) Thin, spreading sheets are the most common growth form of Iva- American Carboniferous brachiopods. Journal of Paleontology 71, 34–53. Li, C.Q., Zhao, J.M., 1993. Upper Carboniferous rugose corals from Xintang, Panxian, novia in the study region. A mini-domal growth form is also found. Guizhou (in Chinese with English summary). Acta Palaeontologica Sinica 32 (6), Ivanovia employed peripheral, medial and mixed growth strategies 765–772. to occupy a sufficient living space on the substrate. The colony size Li, R.F., Liu, B.P., Zhao, C.L., 1996. Characteristics of cycle-sequence, carbon isotope of Ivanovia encrusting carbonate hardgrounds (in situ) is relatively features and glacio-eustasy of the Triticites zone in Southern Guizhou (in Chinese with English abstract). Acta Geologica Sinica 70 (4), 342–350. larger than colonies on other types of hard substrate. Liu, B.P., Li, R.F., Zhao, C.L., 1994. Carboniferous sequence stratigraphy and glacio-eustasy 3) Ivanovia favored shallow, warm, and clear marine environments of Triticites zone in Southern Guizhou, China (in Chinese with English abstract). — – within the photic zone. The Pennsylvanian encrusting Ivanovia of Earth Science Journal of China University of Geosciences 19 (5), 553 564. Molineux, A., 1994. A Late Pennsylvanian encruster: terminal Paleozoic calcified south Guizhou tolerated significant water movement. In shallow, demosponge? Canadian Society of Petroleum Geologists, Memoir 17, 967–982. higher energy conditions, the growth forms and internal structures Nakazawa, T., 2001. Carboniferous reef succession of the Panthalassan open-ocean – of Ivanovia were influenced by ambient environments. Ivanovia setting: example from Omi Limestone, central Japan. Facies 44, 183 210. Palmer, T.J., 1982. Cambrian to Cretaceous changes in hardground communities. Lethaia was generally smothered and covered by mud. The thin, spreading 15, 309–323. sheets, growing closely juxtaposed near and above one another, Powers, B.G., Ausich, W.L., 1990. Epizoan associations in a Lower Mississippian are a reflection of the frequent depositional environment changes. paleocommunity (Borden Group: Indiana: United States of America). Historical Biology 4, 245–265. The Ivanovia community, characterized by low diversity, conforms Riding, R., 1999. The term stromatolite; towards an essential definition. Lethaia 32, to the evolutionary pattern of hard substrate marine communities 321–330. in the Carboniferous. Riding, R., 2006. Microbial carbonate abundance compared with fluctuations in metazoan diversity over geological time. Sedimentary Geology 185, 229–238. Riding, R., Guo, L., 1992. Affinity of Tubiphytes. Palaeontology 35, 37–49. Scotese, C.R., 1997. Paleogeographic atlas, PALEOMAP Progress Report 90-0497. Acknowledgements Department of Geology, University of Texas at Arlington, USA, p. 37. Scrutton, C.T., 1998. The Palaeozoic corals, II: structure, variation and palaeoecology. Financial support for this research was provided by the National Proceedings of the Yorkshire Geological Society 52, 1–57 Part 1. Senowbari-Daryan, B., Flügel, E., 1993. Tubiphytes Maslov, an enigmatic fossil: Natural Science Foundation of China (Project No. 40572014). We wish classification, fossil record and significance through time. Bollettino della Societa to thank Carlton E. Brett and Franz T. Fürsich for making valuable Paleontologica Italiana. Special Volume 1, 353–382. suggestions and language corrections. Shapiro, R.S., 2002. A comment on the systematic confusion of thrombolites. Palaios 15, 166–169. Shen, J.W., Xu, H.L., 2005. Microbial carbonates as contributors to Upper Permian References (Guadalupian–Lopingian) biostromes and reefs in carbonate platform margin setting, Ziyun County, South China. Palaeogeography, Palaeoclimatology, Palaeoe- Alvarez, F., Taylor, P.D., 1987. Epizoan ecology and interactions in the Devonian of Spain. cology 218, 217–238. Palaeogeography, Palaeoclimatology, Palaeoecology 61, 17–31. Suchy, D.R., West, R.R., 1988. A Pennsylvanian cryptic community associated with Brett, C.E., 1988. Paleoecology and evolution of marine hard substrate communities: an laminar chaetetid colonies. Palaios 3, 404–412. overview. Palaios 3, 374–378. Sumrall, C.D., Sprinkle, J., Bonem, R.M., 2006. An edrioasteroid-dominated echinoderm Carozzi, A.V., 1989. Carbonate Rock Depositional Models: A Microfacies Approach. assemblage from a Lower Pennsylvanian marine conglomerate in Oklahoma. Prentice Hall, Englewood Cliffs, NJ. 604 pp. Journal of Paleontology 80 (2), 229–244. Cossey, P.J., Mundy, D.J., 1990. Tetrataxis: a loosely attached limpet-like foraminifer from Sun, B.L., Gong, E.P., Guan, C.Q., Yao, Y.Z., Zhang, Y.L., 2007. Sedimentary environment the Upper Palaeozoic. Lethaia 23, 311–322. and microfacies analysis of a Carboniferous coral reef in the Bianping Village of Ding, Y.J., Xia, G.Y., Xu, S.Y. (Eds.), 1992. The Carboniferous–Permian boundary in China Ziyun County, Guizhou (in Chinese with English abstract). Acta Sedimentologica (in Chinese with English abstract). Geological Publishing House, Beijing, p. 170. Sinica 25 (3), 351–357. Edwards, J.R., Marcus, S.A., 1993. An unusual Upper Carboniferous hardground from the Taylor, P.D., 1985. Carboniferous and Permian species of the cyclostome bryozoan Cor- southeastern part of the Peoples Republic of China. Geological Society of America ynotrypa Bassler, 1911 and their clonal propagation. Bulletin of the British Museum, Abstracts With Programs 25 (6), 104. Natural History, Geology Series 38, 359–372. Fan, J., Rigby, J.K., 1994. Upper Carboniferous phylloid algal mounds in Southern Taylor, P.D., Wilson, M.A., 2003. Palaeoecology and evolution of marine hard substrate Guizhou, China. Brigham Young University Geology Studies 40, 17–24. communities. Earth-Science Reviews 62, 1–103. Feng, Z.Z., Yang, Y.Q., Bao, Z.D., 1999. Lithofacies palaeogeography of the Carboniferous Tian, S.G., Fan, J.S., 2001. Early–Middle Permian reef frameworks and reef-building in South China (in Chinese with English abstract). Journal of Palaeogeography 1 (1), models in the Eastern Kunlun Mountains. Acta Geologica Sinica 75 (2), 115–125. 75–86. Wang, J.D., Li, H.M., 1998. Carboniferous paleo-latitude and bauxite deposit of central GGMRB (Guizhou Geology, Mineral Resource Bureau), 1987. The Guizhou Regional Guizhou province (in Chinese with English abstract). Geochimica 27 (6), 575–578. Geology (in Chinese with English abstract). Geological Publishing House, Beijing. Wang, Z.H., Qi, Y.P., 2002. Restudy of the conodont sequence across the Carboniferous– 698 pp. Permian boundary in South Guizhou. Acta Micropalaeontologica Sinica 19 (3), 228–236. Gong, E.P., Fan, J.S., 2000. Early period of early Permian tubular cyanobacteria reef in Wang, S.H., Fan, J.S., Rigby, J.K., 1994. Archaeolithoporella and Tubiphytes:affinities and eastern part of south Qinling Mountains. Science in China (Series D) 43 (4), paleoecology in Permian reefs of South China. Science in China (Series B) 37 (6), 347–355. 723–743. Gong, E.P., Yang, H.Y., Guan, C.Q., Sun, B.L., Yao, Y.Z., 2004. Unique recovery stage of reef Wang, Y.B., Zhang, K.X., Gong, Y.M., Zhang, Z., Luo, M.S., 1998. The discovery of Early communities after F/F event in a huge coral reef of Carboniferous, Southern Permian reef belt in east Kunlun and its significance. Chinese Science Bulletin 43 Guizhou, China. Science in China (Series D) 47 (5), 412–418. (11), 947–950. 516 Y. Zhang et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 280 (2009) 507–516

Wang, Z.J., Hou, H.F., Lin, Y.D. (Eds.), 1990. Carboniferous System in China (in Chinese Wilson, M.A., Palmer, T.J., Guensburg, T.E., Finton, C.D., Kaufman, L.E., 1992. The with English abstract). Geological Publishing House, Beijing, p. 419. development of an Early Ordovician hardground community in response to rapid Webb, G.E., 1993. A Lower Pennsylvanian encrusting tabulate coral from a rocky shore sea-ﬂoor calcite precipitation. Lethaia 25, 19–34. environment developed on the Mississippian–Pennsylvanian unconformity surface Wood, R., 1995. The changing biology of reef-building. Palaios 10, 517–529. in Northwestern Arkansas. Journal of Paleontology 67, 1064–1068. Wu, X.H., 1987. The Carboniferous biostratigraphy of Guizhou Province, China (in Wilson, M.A., 1987. Ecological dynamics on pebbles, cobbles, and boulders. Palaios 2, Chinese with English abstract). Acta Geologica Sinica 4, 285–295. 594–599. Zhang, X.H., 2002. The Late Carboniferous and Early Permian rugose corals from Ziyun Wilson, M.A., Palmer, T.J., 1992. Hardgrounds and hardground faunas. University of County and Qinglong County, South Guizhou (in Chinese with English summary). Wales, Aberystwyth, Institute of Earth Studies Publications 9, 1–131. Acta Palaeontologica Sinica 41 (2), 283–292. Wilson, M.A., Palmer, T.J., Guensburg, T.E., Finton, C.D., 1989. Sea ﬂoor cementation and Zhang, Y.L., Gong, E.P., Guan, C.Q., Samankassou, E., Sun, B.L., 2007. Carboniferous the development of hard substrate communities: new evidence from Cambro– phylloid algal reefs in Ziyun County, Guizhou (South China): evidence of algal Ordovician hardgrounds in Nevada and Utah. Geological Society of America Annual blooms (in Chinese with English abstract). Acta Sedimentologica Sinica 25 (2), Meeting, Abstracts With Programs 21, 253–254. 177–182.